BIG Problem

[MN]

I just completed assembling a computer. It is based upon the MSI MS-7265
mobo and Morex 6610 case (with 250 watt power supply). It is a mini-ITX
computer and includes a SATA hard-drive, an IDE (PATA) CD/DVD burner and a
3.5" floppy. (The latter can come in handy, sometimes.)

Needless to say, it was a tight fit, with the cables to the mobo the most
difficult and tedious part -- especially the cable dressing. I was careful
during assembly, using a grounded wrist strap-- especially when placing the
memory strips, cpu, and CPU-fan onto the mobo. I had all the docs & info at
my finger tips which was needed to correctly place the numerous connections
to the mobo headers/connectors (e.g. SATA. IDE, USB, power button switch and
LED, etc.).

Well, I applied AC power to the computer with the case-cover off and NO
connections to the monitor, mouse and keyboard. I expected to see the CPU
fan running and some beeping since the was no mouse or keyboard connected.
Much to my disappointment, NOTHING happened. So, I realized that I would
have to diagnose what is wrong.

First, I checked the AC-cord and made sure it was OK, and also connected the
computer to different AC outlets -- to make sure that the AC input was OK.
Then I measured voltages on the power-supply's 20-pin main ATX connector. I
found the requisite standby 5 volts on pin 9 (purple wire) and pin 14
(green wire). This is correct with no signal from the mobo.

Next, I need to JUMPER pins on the 20-pin ATX connector the simulate the
mobo's OK signal to the power supply. I don't KNOW which pins to jumper to
see if the power supply will output the other voltages on other pins. My
pinout diagram just lists the pin #, wire color, and voltage value --so I
can't determine which pins to jumper. I WANT TO BE SURE TO JUMPER THE
CORRECT PINS!

Please advise my of the pins to jumper, and other steps to perform in my
diagnosis.

 

[Paul]

I just completed assembling a computer. It is based upon the MSI MS-7265
mobo and Morex 6610 case (with 250 watt power supply). It is a mini-ITX
computer and includes a SATA hard-drive, an IDE (PATA) CD/DVD burner and a
3.5" floppy. (The latter can come in handy, sometimes.)

Needless to say, it was a tight fit, with the cables to the mobo the most
difficult and tedious part -- especially the cable dressing. I was careful
during assembly, using a grounded wrist strap-- especially when placing the
memory strips, cpu, and CPU-fan onto the mobo. I had all the docs & info at
my finger tips which was needed to correctly place the numerous connections
to the mobo headers/connectors (e.g. SATA. IDE, USB, power button switch and
LED, etc.).

Well, I applied AC power to the computer with the case-cover off and NO
connections to the monitor, mouse and keyboard. I expected to see the CPU
fan running and some beeping since the was no mouse or keyboard connected.
Much to my disappointment, NOTHING happened. So, I realized that I would
have to diagnose what is wrong.

First, I checked the AC-cord and made sure it was OK, and also connected the
computer to different AC outlets -- to make sure that the AC input was OK.
Then I measured voltages on the power-supply's 20-pin main ATX connector. I
found the requisite standby 5 volts on pin 9 (purple wire) and pin 14
(green wire). This is correct with no signal from the mobo.

Next, I need to JUMPER pins on the 20-pin ATX connector the simulate the
mobo's OK signal to the power supply. I don't KNOW which pins to jumper to
see if the power supply will output the other voltages on other pins. My
pinout diagram just lists the pin #, wire color, and voltage value --so I
can't determine which pins to jumper. I WANT TO BE SURE TO JUMPER THE
CORRECT PINS!

Please advise my of the pins to jumper, and other steps to perform in my
diagnosis.

Jumper PS_ON# to COM, to turn on a supply. There are specs of various sorts
here if you need them. The third spec is for 24 pin supplies. Grounding
PS_ON# means "turn on please".

http://web.archive.org/web/20030424...org/developer/specs/atx/ATX_ATX12V_PS_1_1.pdf

http://www.formfactors.org/developer/specs/atx/ATX12V_1_3dg.pdf

http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2.pdf

*******

And don't be in too big of a rush when doing that!

The thing is, when you jumper PS_ON# to COM, you defeat some
safety features. Some motherboards are designed to turn off
the computer, if they detect CPU overheat. Using the jumper
method, means the motherboard can't turn off the supply when
it wants to.

I would set up the system on my work bench, and verify it works
first. Then spend the tedious hours doing installation and cable dress
and the like. I've done that for a few builds here, choosing to assemble
the motherboard while it sits on a piece of cardboard (or a telephone book).
I've actually had the Windows screen showing, while all the hardware
was strewn about the bench. The most dangerous part of that method,
is the fact the video card has no mechanical support (except for the
slot connector). Don't allow any small kids in the work area, as they
may pull out the video card or cable and ruin the card or motherboard.
A slight tug on the video cable is all it takes.

Check that your front power switch, is inserted on the correct two
pins of the PANEL connector.

You can also use a screwdriver tip, to momentarily contact the two
PWR switch pins on the panel connector. The switch type is momentary
contact, so a screwdriver tip, touched to the two pins in question,
will simulate a power switch. But use extreme care when doing so.
That technique is only practical, if you have clear, line of
sight access, to the PANEL header, and can hit the two pins
accurately. You don't want to short something else and ruin it.

There is a difference between the two interfaces on the computer.
The PWR switch pins on the PANEL header are momentary contact.
Only a slight touch of the two pins, turns it on. The PS_ON#
signal on the ATX power supply cable, is level sensitive. You
have to keep a shunt to COM present, for as long as you want
the supply to be running. A momentary contact there is not
enough - PS_ON# needs a steady level.

Paul

 

[LSMFT]

I just completed assembling a computer. It is based upon the MSI MS-7265
mobo and Morex 6610 case (with 250 watt power supply). It is a mini-ITX
computer and includes a SATA hard-drive, an IDE (PATA) CD/DVD burner and a
3.5" floppy. (The latter can come in handy, sometimes.)

Needless to say, it was a tight fit, with the cables to the mobo the most
difficult and tedious part -- especially the cable dressing. I was careful
during assembly, using a grounded wrist strap-- especially when placing the
memory strips, cpu, and CPU-fan onto the mobo. I had all the docs& info at
my finger tips which was needed to correctly place the numerous connections
to the mobo headers/connectors (e.g. SATA. IDE, USB, power button switch and
LED, etc.).

Well, I applied AC power to the computer with the case-cover off and NO
connections to the monitor, mouse and keyboard. I expected to see the CPU
fan running and some beeping since the was no mouse or keyboard connected.
Much to my disappointment, NOTHING happened. So, I realized that I would
have to diagnose what is wrong.

First, I checked the AC-cord and made sure it was OK, and also connected the
computer to different AC outlets -- to make sure that the AC input was OK.
Then I measured voltages on the power-supply's 20-pin main ATX connector. I
found the requisite standby 5 volts on pin 9 (purple wire) and pin 14
(green wire). This is correct with no signal from the mobo.

Next, I need to JUMPER pins on the 20-pin ATX connector the simulate the
mobo's OK signal to the power supply. I don't KNOW which pins to jumper to
see if the power supply will output the other voltages on other pins. My
pinout diagram just lists the pin #, wire color, and voltage value --so I
can't determine which pins to jumper. I WANT TO BE SURE TO JUMPER THE
CORRECT PINS!

Please advise my of the pins to jumper, and other steps to perform in my
diagnosis.

It's green and black.

 

[MN]

Paul,
Thanx for your prompt reply and VERY useful info.

I did jumper PS_ON# to COM, to turn on the power supply. Then I measured
the voltages at the 20-pin ATX power connector. They were ALL OK! Then I
went to the 4-pin 12-volt power connector. AHA! This was NOT the12-volt
power connector -- although it looked almost identical (but without the side
latch). I was fooled since it was tie-wrapped close to the 20-pin ATX
connector. I then "dug-out" the REAL 4-pin 12-volt power connector; it's
voltages measured OK.

Next, I removed the jumper and DVM, and I connected the 2 power connectors
to the mobo. Then, I plugged-in the computer, and pressed the power
on/power-off button. After a few seconds (that's long?), the on/off button
"glowed blue" and the CD/DVD led started blinking like normal. Also, I could
eject/retract the CD/DVD disk tray by pressing the appropriate button on the
front faceplate of the CD/DVD. That's the GOOD news.

However, when I pressed the power on/power-off button, "power did NOT go
off' as indicated by the blue LED at the center of the the power
on/power-off button. What does this mean?

Also, the CPU fan did NOT rotate nor were there any audible beep codes. Of
course, if the CPU was not running, the BIOS code would not execute and
generate any beeps, etc. So, now what. Can we conclude that the CPU is NOT
running as indicated by the CPU fan not rotating -- OR -- is the CPU fan not
rotating because the temperature is not "hot enough"?

I am really perplexed. I am glad that the PS is OK and also of the minor
functionality as indicated by the CD/DVD activity, but I don't have a
rational hypothesis where to proceed next. In other words "WHAT DO I DO
NEXT"? to advance "from first base".

Please advise.

Regards,
Marty

============================================================================

 

[MN]

Thanx LSMFT,

I did the jumpering. Please see my reply to Paul in my previous post to see
where I am now.

======================================================================

 

[Jan Alter]

It's green and black.

--
LSMFT

I haven't spoken to my wife in 18 months.
I don't like to interrupt her.

One thing (as I'm running out the door) make sure you have the 4 pin square
plug from the PS for the cpu plugged into the mb or you won't get any power
to the cpu. I see you have 'cpu' listed but I'm just second guessing that's
what you mean.
Good luck

 

[Paul]

Paul,
Thanx for your prompt reply and VERY useful info.

I did jumper PS_ON# to COM, to turn on the power supply. Then I measured
the voltages at the 20-pin ATX power connector. They were ALL OK! Then I
went to the 4-pin 12-volt power connector. AHA! This was NOT the12-volt
power connector -- although it looked almost identical (but without the side
latch). I was fooled since it was tie-wrapped close to the 20-pin ATX
connector. I then "dug-out" the REAL 4-pin 12-volt power connector; it's
voltages measured OK.

Next, I removed the jumper and DVM, and I connected the 2 power connectors
to the mobo. Then, I plugged-in the computer, and pressed the power
on/power-off button. After a few seconds (that's long?), the on/off button
"glowed blue" and the CD/DVD led started blinking like normal. Also, I could
eject/retract the CD/DVD disk tray by pressing the appropriate button on the
front faceplate of the CD/DVD. That's the GOOD news.

However, when I pressed the power on/power-off button, "power did NOT go
off' as indicated by the blue LED at the center of the the power
on/power-off button. What does this mean?

Also, the CPU fan did NOT rotate nor were there any audible beep codes. Of
course, if the CPU was not running, the BIOS code would not execute and
generate any beeps, etc. So, now what. Can we conclude that the CPU is NOT
running as indicated by the CPU fan not rotating -- OR -- is the CPU fan not
rotating because the temperature is not "hot enough"?

I am really perplexed. I am glad that the PS is OK and also of the minor
functionality as indicated by the CD/DVD activity, but I don't have a
rational hypothesis where to proceed next. In other words "WHAT DO I DO
NEXT"? to advance "from first base".

Please advise.

Regards,
Marty

Oh, no...

My first reaction is, I thought the pin shapes were different on the ends.
The 20+4 4 pin section has a different pin shape than the 2x2 ATX12V.
Something like this.

S D versus D S where: S = square pin
D S S D D = shaped like the letter D

If you rotate one of those by 180 degrees, the D shape on one would be a
"backwards D", so it shouldn't mate. I'm using the pictures on playtool
to reach this conclusion, and my eyesight isn't the best.

http://www.playtool.com/pages/psuconnectors/connectors.html

The thing is, your 20+4 4 pin section, has +3.3, +5, +12, and Ground on it.
When mated to a connector with two 12V pins and two ground pins, two pairs
of rails end up shorted together. Say, for the sake of argument, that a
12V pin is shorted to a 3.3V pin, because they happen to be shoved into
the two 12V motherboard holes. The 12V power output will attempt to "lift"
the 3.3V output. This could damage the 3.3V circuitry on the motherboard.

The power supply has several forms of protection.

1) Overcurrent. Shorting one of the rails to ground, could cause the
power supply to switch off after 35 milliseconds.

2) Overvoltage. OVP detects wide excursions, like the 3.3V rail being at
4.7V. The supply can be designed to shut off when that
happens. It might even take less than 35 milliseconds.
But sensitive circuits can be blown in less time than that.

Your CPU fan is not rotating. You could take a multimeter, and *carefully*
check the 12V pin on that fan header, and see if it is getting power. To do that
here, I'd make up a custom cable assembly (I have some bags of small fan connectors
and pins), and then take a loose wire from a setup like that, and make a
measurement. Otherwise, it would be dangerous to get the multimeter in amongst
the CPU fan header pins.

The CPU fan draws power from the 12V yellow wire on the main power connector.

The CPU itself draws power from the two yellow wires on the ATX12V connector.

If the CPU gets too hot, while sitting there in that fan-less state,
the computer could shut off. Are you still jumpering PS_ON# ? Now
would be a good time to stop doing that. The overheat safety
feature won't work to protect the CPU, if your PS_ON# is still
jumpered.

I'd swap motherboards. Chances are, your CPU is not damaged. Your
RAM is not damaged. They're protected by the onboard regulators.
There could be damage to the motherboard. You can test your CDROM
and hard drives using another computer. You've verified PSU voltages,
both on the main connector and on the ATX12V, so you suspect the
PSU is OK. Don't forget to check the status pin on the ATX PSU,
the "power good" or whatever it is called, as the power supply
may refuse to assert that, and that would prevent POST on a
new motherboard.

It is pretty hard to judge just what damage has been done. I would
not have thought those two connectors could be mixed up (but I'm not
taking my current computer apart to verify this ) If you did
manage to mate the connectors, one rail got shorted, and another
rail got lifted. Either "insult" should have made a good power
supply shut off. But maybe not fast enough to prevent damage to
the motherboard.

What happens to a CPU fan, is a function of its design. The CPU fan
header could be a three pin or a four pin. A three pin can use voltage
control on the 12V pin. That means a MOSFET may be in series in the path.
Damage to the control circuit might prevent it from powering up.

A four pin CPU fan header, delivers 12V to the 12V pin, and relies
on the PWM pin for fan speed control. That is less likely to stop
spinning entirely. I'd turn off all power, use the ohms scale on the
multimeter, and check for continuity from the 12V pin on the CPU four
pin fan header, to where the 12V wire would plug into the main power
connector.

Other than debugging, I'd swap motherboards, as long as you know for
certain, that the PSU has all good voltages, and has a logic 1 on the
power good output.

Paul

 

[MN]

Paul,

Thanx for your prompt reply and suggestions. I address your ideas/concerns
individually below after the corresponding text. (They are prefixed with
***).

============================================================================

Oh, no...

My first reaction is, I thought the pin shapes were different on the ends.
The 20+4 4 pin section has a different pin shape than the 2x2 ATX12V.
Something like this.

S D versus D S where: S = square pin
D S S D D = shaped like the
letter D

If you rotate one of those by 180 degrees, the D shape on one would be a
"backwards D", so it shouldn't mate. I'm using the pictures on playtool
to reach this conclusion, and my eyesight isn't the best.

http://www.playtool.com/pages/psuconnectors/connectors.html

The thing is, your 20+4 4 pin section, has +3.3, +5, +12, and Ground on
it.
When mated to a connector with two 12V pins and two ground pins, two pairs
of rails end up shorted together. Say, for the sake of argument, that a
12V pin is shorted to a 3.3V pin, because they happen to be shoved into
the two 12V motherboard holes. The 12V power output will attempt to "lift"
the 3.3V output. This could damage the 3.3V circuitry on the motherboard.

The power supply has several forms of protection.

1) Overcurrent. Shorting one of the rails to ground, could cause the
power supply to switch off after 35 milliseconds.

2) Overvoltage. OVP detects wide excursions, like the 3.3V rail being at
4.7V. The supply can be designed to shut off when that
happens. It might even take less than 35 milliseconds.
But sensitive circuits can be blown in less time than
that.

Your CPU fan is not rotating. You could take a multimeter, and *carefully*
check the 12V pin on that fan header, and see if it is getting power. To
do that
here, I'd make up a custom cable assembly (I have some bags of small fan
connectors
and pins), and then take a loose wire from a setup like that, and make a
measurement. Otherwise, it would be dangerous to get the multimeter in
amongst
the CPU fan header pins.

The CPU fan draws power from the 12V yellow wire on the main power
connector.

The CPU itself draws power from the two yellow wires on the ATX12V
connector.

If the CPU gets too hot, while sitting there in that fan-less state,
the computer could shut off. Are you still jumpering PS_ON# ? Now
would be a good time to stop doing that. The overheat safety
feature won't work to protect the CPU, if your PS_ON# is still
jumpered.

I'd swap motherboards. Chances are, your CPU is not damaged. Your
RAM is not damaged. They're protected by the onboard regulators.
There could be damage to the motherboard. You can test your CDROM
and hard drives using another computer. You've verified PSU voltages,
both on the main connector and on the ATX12V, so you suspect the
PSU is OK. Don't forget to check the status pin on the ATX PSU,
the "power good" or whatever it is called, as the power supply
may refuse to assert that, and that would prevent POST on a
new motherboard.

*** I really can't swap mobos, because I don't have another spare
functioning mobo of similar architecture.

It is pretty hard to judge just what damage has been done. I would
not have thought those two connectors could be mixed up (but I'm not
taking my current computer apart to verify this ) If you did
manage to mate the connectors, one rail got shorted, and another
rail got lifted. Either "insult" should have made a good power
supply shut off. But maybe not fast enough to prevent damage to
the motherboard.

*** Regarding the "similar" 4-pin connector: I measured +5 volts on it when
I had both ATX power connectors NOT connected to the mobo, and the PS_ON# to
COM jumper in place. This +5 volts was measured AT THE SAME TIME that I
measured (and found correct) the voltages on both ATX power connectors.
Comment: this +5 volts on the "similar" 4-pin connector is LESS than the +12
volts that the correct 4-pin connector supplies. This is in "my favor" since
the +12 volts that the mobo expected is greater than the +5 volts I possibly
erroneously supplied. Also, (1) after I connected the correct 4-pin ATX
connector AND the 20-pin ATX connector (no jumper, of course), and (2)
applied AC power, and (3) then pressed the case power button, I got the BLUE
LED to illuminate and was able to manually operate the CD/DVD from the front
faceplate. Thus, I believe that my original "application of +5 volts instead
of +12 volts" on the 4-pin connector did NOT damage the mobo. TO DO: I need
to check into the voltages applied to the fan connector when the mobo has
power applied.

QUESTION: SUPPOSE, I did not have the 2 sticks of DDR2 memory in their
sockets, what would be the symptoms? If, for any reason the
read/write/refresh RAM memory cycles were not correct (incorrect default
BIOS memory timing, SPD,etc), it would be as if no RAM memory was present.
Thus my question. In other word, isn't the CPU "dead in the water" without
correctly functioning DDR2 RAM?

What happens to a CPU fan, is a function of its design. The CPU fan
header could be a three pin or a four pin. A three pin can use voltage
control on the 12V pin. That means a MOSFET may be in series in the path.
Damage to the control circuit might prevent it from powering up.

*** TO DO: I need to check into the voltages applied to the fan connector
when the mobo has power applied.

A four pin CPU fan header, delivers 12V to the 12V pin, and relies
on the PWM pin for fan speed control. That is less likely to stop
spinning entirely. I'd turn off all power, use the ohms scale on the
multimeter, and check for continuity from the 12V pin on the CPU four
pin fan header, to where the 12V wire would plug into the main power
connector.

*** The fan header is 3-pin with pins for +12v, sensor, and ground. My
previous TO DO will verify the +12/ground. As for the sensor, ???

 

[Paul]

QUESTION: SUPPOSE, I did not have the 2 sticks of DDR2 memory in their
sockets, what would be the symptoms? If, for any reason the
read/write/refresh RAM memory cycles were not correct (incorrect default
BIOS memory timing, SPD,etc), it would be as if no RAM memory was present.
Thus my question. In other word, isn't the CPU "dead in the water" without
correctly functioning DDR2 RAM?

If you turn off the power, then remove both RAM sticks, the
CPU can still function at the next power up. What should happen,
is the CPU should be able to beep the computer case speaker.
(You need a computer case speaker, connected to the SPKR pins
on the PANEL header on the motherboard.) It might be
two beeps, then silence, two beeps, then silence and so on.
If you hear beeps, then it means the CPU is working a little
bit. If it still won't beep, then the CPU might not be
executing any code at all.

Another way to prove the CPU is executing code, is to insert
a PCI Port 80 POST card, into the PCI slot #1 (that is the
PCI slot nearest to the processor). The codes don't mean a whole
lot, that flash on the card, but just getting the code value
to change, from the initial 0x00 or 0xFF value is an achievement.
You'd either have to borrow or buy one of those. They can be
real cheap when ordered from Hong Kong via Ebay, while if you
buy one from a local computer store, they can be $100.00.

(This one from Startech is $40 or so. One reviewer says it
only works in 5V PCI slots, not 3.3V ones. 5V slots are
relatively common. I think all my motherboards here have
5V slots. Some products like this, come with a second
display on the end of a ribbon cable, which makes it easier
to read the display.)

http://www.startech.com/Share/Gallery/Large/PCIPOST.Alarge.jpg

This one plugs into PCI and ISA slots. I only have one
computer with ISA slots here (11 years old). This one has
a second display on the ribbon cable, to aid visibility.

http://www.elstonsystems.com/prod/pc_post_diagnostic_card.html

Some limited number of motherboards, have four status LEDs. Some
even have the port 80 display soldered right onto the motherboard,
for easy reference. But to keep motherboard costs down, they
don't bother with that most of the time.

Asus used to provide a Winbond voice chip at one time, and it would
"speak" an error code. The solution probably cost a buck or two
per motherboard, but did add some value. But they've stopped using those,
and no other motherboard manufacturer seemed to be interested in
doing the same thing. I have a couple motherboards here, with that
error information voice device on it. The sound comes out of the external
computer speakers, via the green audio jack on the motherboard.

Good luck,
Paul

 

[larry moe 'n curly]

*** Regarding the "similar" 4-pin connector: I measured +5 volts on it when
I had both ATX power connectors NOT connected to the mobo, and the PS_ON# to
COM jumper in place. This +5 volts was measured AT THE SAME TIME that I
measured (and found correct) the voltages on both ATX power connectors.
Comment: this +5 volts on the "similar" 4-pin connector is LESS than the +12
volts that the correct 4-pin connector supplies. This is in "my favor" since
the +12 volts that the mobo expected is greater than the +5 volts I possibly
erroneously supplied. Also, (1) after I connected the correct 4-pin ATX
connector AND the 20-pin ATX connector (no jumper, of course), and (2)
applied AC power, and (3) then pressed the case power button, I got the BLUE
LED to illuminate and was able to manually operate the CD/DVD from the front
faceplate. Thus, I believe that my original "application of +5 volts instead
of +12 volts" on the 4-pin connector did NOT damage the mobo. TO DO: I need
to check into the voltages applied to the fan connector when the mobo has
power applied.

QUESTION: SUPPOSE, I did not have the 2 sticks of DDR2 memory in their
sockets, what would be the symptoms? If, for any reason the
read/write/refresh RAM memory cycles were not correct (incorrect default
BIOS memory timing, SPD,etc), it would be as if no RAM memory was present.
Thus my question. In other word, isn't the CPU "dead in the water" without
correctly functioning DDR2 RAM?

First of all, I wouldn't test a new computer with the disk drives
installed but the keyboard and monitor not connected because the video
and keyboard can indicate some signs of life in the computer. At
least you had the mobo speaker installed.

Another thing I do with new mobos is first remove the CMOS battery
because when the CMOS clock memory contents is gone, most mobos will
turn on instantly when power is applied, even before the power switch
pins on the mobo aren't shorted together, plus the CPU fan will
probably run at full speed, rather use any quiet mode that may not
turn on the fan until the CPU warms up enough.

I have a feeling Paul is right about damage occurring because the two
different square 4-pin power connectors were mixed up. Connectors are
supposed to be molded to make that impossible, but that wasn't the
situation with my Ultra V-series PSU and a cheap ECS mobo. It's
possible that damage was limited to a protective fuse (flat
rectangular surface mount thing, often black or green on top and
marked "F" or "X" on top or on the mobo) and diode (diode may have
blown the fuse and shorted in the process). These devices are often
near the power connectors. Try measuring the resistance across each,
in both directions.

I think you should test the mobo outside of the case, to rule out any
shorts between the mobo and case. Be sure to set the mobo on top of a
non-metallic anti-static surface, such as the foam sheet packed with
the mobo or some pink transparent bubble wrap. Put that on top of
3/4" brown cardboard, brown paper, or non-shiney newspaper.

 

[MN]

Paul,
Thanx for the info. Please see my comments below (prefixed by ***)

If you turn off the power, then remove both RAM sticks, the
CPU can still function at the next power up. What should happen,
is the CPU should be able to beep the computer case speaker.
(You need a computer case speaker, connected to the SPKR pins
on the PANEL header on the motherboard.) It might be
two beeps, then silence, two beeps, then silence and so on.
If you hear beeps, then it means the CPU is working a little
bit. If it still won't beep, then the CPU might not be
executing any code at all.

*** There is no computer case speaker, nor are there any SPKR pins
on the PANEL header. However, the mobo probably has a piezo-electric chip
that can emit beeps.

Another way to prove the CPU is executing code, is to insert
a PCI Port 80 POST card, into the PCI slot #1 (that is the
PCI slot nearest to the processor). The codes don't mean a whole
lot, that flash on the card, but just getting the code value
to change, from the initial 0x00 or 0xFF value is an achievement.
You'd either have to borrow or buy one of those. They can be
real cheap when ordered from Hong Kong via Ebay, while if you
buy one from a local computer store, they can be $100.00.

(This one from Startech is $40 or so. One reviewer says it
only works in 5V PCI slots, not 3.3V ones. 5V slots are
relatively common. I think all my motherboards here have
5V slots. Some products like this, come with a second
display on the end of a ribbon cable, which makes it easier
to read the display.)

http://www.startech.com/Share/Gallery/Large/PCIPOST.Alarge.jpg

This one plugs into PCI and ISA slots. I only have one
computer with ISA slots here (11 years old). This one has
a second display on the ribbon cable, to aid visibility.

http://www.elstonsystems.com/prod/pc_post_diagnostic_card.html

Some limited number of motherboards, have four status LEDs. Some
even have the port 80 display soldered right onto the motherboard,
for easy reference. But to keep motherboard costs down, they
don't bother with that most of the time.

*** A PCI Port 80 POST card is interesting, especially since the mobo manual
lists 6 pages of Award post codes (although it is noted to be incomplete).
However, I am first thinking of connecting my monitor to the mobo's VGA
connector (within the I/O shield). Maybe there will be something on the
screen. (I am hoping that the default BIOS video-output setting is for the
video out to go to the VGA connector instead of the DVI connector, which is
also provided.)

 

[John Doe]

I think you should test the mobo outside of the case, to rule
out any shorts between the mobo and case.

There are many shorts between the motherboard and the case, that
is in part the purpose for metal standoffs connected to
motherboard conductive points. The likelihood of determining there
is an unintentional short between the motherboard and the case is
no greater than the likelihood of some random change causing the
motherboard to work outside of the case. The case is an extremely
good project holder for a motherboard, it should be used for that.
If I suspected unintentional shorts between the motherboard and
the case, I would test by using a different case. If you really
knew what you were doing, you could use a continuity tester to
determine whether there are any unintentional shorts between the
motherboard and the case. And of course an ordinary user would
have his computer turned off and unplugged from the wall before
sticking metal probes into it for any purpose.
--

 

[larry moe 'n curly]

There are many shorts between the motherboard and the case, that
is in part the purpose for metal standoffs connected to
motherboard conductive points.

I mean shorts to ponts that aren't meant to be grounds, such as when a
signal or voltage trace runs so close to a mounting hole that it
touches the screw or brass standoff.

The likelihood of determining there
is an unintentional short between the motherboard and the case is
no greater than the likelihood of some random change causing the
motherboard to work outside of the case.

But motherboards often work when removed from the case.

 

[MN]

Thanx for your suggestions. Please see my comments below, prefixed by ***

============================================================================

First of all, I wouldn't test a new computer with the disk drives
installed but the keyboard and monitor not connected because the video
and keyboard can indicate some signs of life in the computer. At
least you had the mobo speaker installed.

*** I connected the monitor and keyboard to the computer. Then I plugged in
the AC line cord, and pressed the case power button. The case power BLUE LED
illuminated and I was able to manually perform CD/DVD tray ejection from
the front faceplate, just as before I had a monitor & keyboard connected.
There was NOTHING on the screen and NO beeping. (There is no case speaker,
and NO pins on the mobo PANEL header to connect to a case speaker.
Therefore, I assume there is a piezo electric chip on the mobo to do any
beeping.) CONCLUSION: the bios is not executing because the CPU is not
running.

Another thing I do with new mobos is first remove the CMOS battery
because when the CMOS clock memory contents is gone, most mobos will
turn on instantly when power is applied, even before the power switch
pins on the mobo aren't shorted together, plus the CPU fan will
probably run at full speed, rather use any quiet mode that may not
turn on the fan until the CPU warms up enough.

*** I will try this, but will it help if the CPU is not running?

I have a feeling Paul is right about damage occurring because the two
different square 4-pin power connectors were mixed up. Connectors are
supposed to be molded to make that impossible, but that wasn't the
situation with my Ultra V-series PSU and a cheap ECS mobo. It's
possible that damage was limited to a protective fuse (flat
rectangular surface mount thing, often black or green on top and
marked "F" or "X" on top or on the mobo) and diode (diode may have
blown the fuse and shorted in the process). These devices are often
near the power connectors. Try measuring the resistance across each,
in both directions.

*** I don't think I caused any damage because the incorrect 4-pin connector
supplied +5volts instead of the normal +12 volts on the correct connector.

I think you should test the mobo outside of the case, to rule out any
shorts between the mobo and case. Be sure to set the mobo on top of a
non-metallic anti-static surface, such as the foam sheet packed with
the mobo or some pink transparent bubble wrap. Put that on top of
3/4" brown cardboard, brown paper, or non-shiney newspaper.

*** I will take the mobo out of the case. But if it is not grounded to the
case by the mounting screw/standoffs, won't this be a problem?

 

[Paul]

*** I will take the mobo out of the case. But if it is not grounded to the
case by the mounting screw/standoffs, won't this be a problem?

Ground is provided in three ways on a motherboard.

1) The black wires on the main ATX power supply cable are ground.

2) Where the conducting motherboard tray standoffs touch the
bottom of the motherboard, on the plated_thru holes, is ground.
The purpose of the ground, may be for RF emissions control, rather
than DC current conduction.

3) The I/O plate inserted in the computer case, has shiny springy
metal contacts. They press against the I/O stack shiny metal body.
That causes chassis ground to electrically touch and contact the
stack. That is for ESD discharge and RF EMI control as well.

If you place a motherboard on a cardboard covered telephone book,
you lose (2) and (3), but (1) has you more than covered. The
DC return currents continue to flow over the black wires and
all is good.

I've built and tested two computers, sitting on telephone books,
and they worked fine. No instability, no complaints. Once tested,
I disassembled and placed the components into the case as normal,
knowing all the hardware was working.

Paul

 

[MN]

Paul,
I took the mobo out of the case and placed it on cardboard. I applied AC
power and was able to get the case power LED to glow in response to pressing
the case power button. I still do not get (1) any beeps from the
piezo-electric beeper (I can see the piezo on the mobo), (2) no movement of
the CPU-mounted fan (3-wire connection to mobo for speed control), and (3)
any output on the monitor. All of the above were true before and after I
removed all connections to the mobo, other than the 20-pin and 4-pin power
connectors as well as removal of the DDR2 memory sticks. The logical
conclusion, as indicated by items (1) thru (3) above is that the CPU is NOT
running -- since EACH of those items requires the CPU to execute BIOS code.
Furthermore, I cleared the CMOS data by applying the jumper as per the
manual's instructions, and also measured the CMOS battery voltage to be 3
volts. (I used a wrist strap connected to ground when working on the mobo.)

The processor I installed was an new Intel socket M Core-Duo processor T2450
(SLA4M). It is a PGA package device. The mobo supports a broad range of
socket-M PGA CPUs, both single and dual core including a CeleronM. I don't
think I have am using an incompatible CPU. Thus the question is: WHY ISN'T
THE CPU RUNNING AND EXECUTING BIOS CODE? Observation: I do sense a very
slight warmth under the CPU when the power is ON. All I definitely know is
that the power supply provides the correct voltages to the mobo and the
mobo's hardwired power-button & associate LED logic functions.

Could there be connection problems between the mounted CPU and the mobo
socket? I guess I can remove and reinstall the CPU and heat-sink/fan to find
out. Any other suggestions?

-Marty

 

[Paul]

Paul,
I took the mobo out of the case and placed it on cardboard. I applied AC
power and was able to get the case power LED to glow in response to pressing
the case power button. I still do not get (1) any beeps from the
piezo-electric beeper (I can see the piezo on the mobo), (2) no movement of
the CPU-mounted fan (3-wire connection to mobo for speed control), and (3)
any output on the monitor. All of the above were true before and after I
removed all connections to the mobo, other than the 20-pin and 4-pin power
connectors as well as removal of the DDR2 memory sticks. The logical
conclusion, as indicated by items (1) thru (3) above is that the CPU is NOT
running -- since EACH of those items requires the CPU to execute BIOS code.
Furthermore, I cleared the CMOS data by applying the jumper as per the
manual's instructions, and also measured the CMOS battery voltage to be 3
volts. (I used a wrist strap connected to ground when working on the mobo.)

The processor I installed was an new Intel socket M Core-Duo processor T2450
(SLA4M). It is a PGA package device. The mobo supports a broad range of
socket-M PGA CPUs, both single and dual core including a CeleronM. I don't
think I have am using an incompatible CPU. Thus the question is: WHY ISN'T
THE CPU RUNNING AND EXECUTING BIOS CODE? Observation: I do sense a very
slight warmth under the CPU when the power is ON. All I definitely know is
that the power supply provides the correct voltages to the mobo and the
mobo's hardwired power-button & associate LED logic functions.

Could there be connection problems between the mounted CPU and the mobo
socket? I guess I can remove and reinstall the CPU and heat-sink/fan to find
out. Any other suggestions?

-Marty

CPU-World says that processor is socket M and they provide this page with
information on the socket.

http://www.cpu-world.com/Sockets/Socket M (mPGA478MT).html

"Instead, the socket has a special actuator that needs to be turned
by about half-turn to lock or release the processor."

That is a zero insertion force (ZIF) socket, where instead of a lever to
work the contacts, a screw closes the contacts. You can see the lock screw
at one end of each socket picture.

Paul

 

[MN]

Paul,
Thanx again. I do have that info and originally used it (together with
the T2450 Intel data sheet) in determining the appropriate chip to purchase.

When I installed the CPU (which could only be inserted one way because
of the blocked pin-hole in the mobo CPU socket), I did tighten the ZIF screw
to clamp the pins tight. Then, (1) I placed the backplate for the
heatsink/fan assy on the underside of the mobo, and (2) screwed the
heatsink/fan assy (on the top side of the mobo) threw the mobo holes into
the mated threads of the backplate. In adjusting the 4 spring-loaded
corner-screws, there was no stop provided, so one could conceivably
overtighten the heatsink/fan assy onto the CPU. (The ZIF lever, used on
other CPUs did not present that situation and was a lot easier than
adjusting 4 screws while holding the heatsink/fan assy and backplate at the
same time). (Comment: I wondered if the metallic surface of the backplate
might short some metallic traces on the underside of the mobo.)

I am going to remove the heatsink/fan assy and see if the CPU looks
damaged due to overtightening. Assuming the CPU does not appear damaged, and
appears to be tight in its socket, I plan to power up the mobo, temporarily,
without the heatsink/fan assy installed. I should hear beeping if the CPU
is running BIOS code. If not, I may remove the CPU, reinstall it, and try
again. I really don't like removing the thermal contact between the heatsink
and CPU surface; I don't have any thermal paste to apply when I re-install
the heatsink/fan assy.

==========================================================

 

[Paul]

Paul,
Thanx again. I do have that info and originally used it (together with
the T2450 Intel data sheet) in determining the appropriate chip to purchase.

When I installed the CPU (which could only be inserted one way because
of the blocked pin-hole in the mobo CPU socket), I did tighten the ZIF screw
to clamp the pins tight. Then, (1) I placed the backplate for the
heatsink/fan assy on the underside of the mobo, and (2) screwed the
heatsink/fan assy (on the top side of the mobo) threw the mobo holes into
the mated threads of the backplate. In adjusting the 4 spring-loaded
corner-screws, there was no stop provided, so one could conceivably
overtighten the heatsink/fan assy onto the CPU. (The ZIF lever, used on
other CPUs did not present that situation and was a lot easier than
adjusting 4 screws while holding the heatsink/fan assy and backplate at the
same time). (Comment: I wondered if the metallic surface of the backplate
might short some metallic traces on the underside of the mobo.)

I am going to remove the heatsink/fan assy and see if the CPU looks
damaged due to overtightening. Assuming the CPU does not appear damaged, and
appears to be tight in its socket, I plan to power up the mobo, temporarily,
without the heatsink/fan assy installed. I should hear beeping if the CPU
is running BIOS code. If not, I may remove the CPU, reinstall it, and try
again. I really don't like removing the thermal contact between the heatsink
and CPU surface; I don't have any thermal paste to apply when I re-install
the heatsink/fan assy.

Visually examine the backplate. Some of them have insulation to prevent
accidental contact with components. When the motherboard designer is
laying out the board, there are usually "keepout zones" defined to the
mechanical features, and that is how backplate/heatsink makers are
supposed to stay out of trouble. You'll see white lines on the motherboard,
showing the profile of the backplate location or where the heatsink is expected
to go on the top of the motherboard. Those white lines are intended to show
the keepout zones defined in the layout tool.

With regard to thermal paste, you should always have at least one tube
on hand. I have a $5 tube that I've been using for years. A little
bit of it, goes a long way. If the current material is scratched up,
distorted or it is preventing the heatsink from sitting flat, then
clean off the existing material and apply some paste. You never want
the paste to get on components (tiny resistors or capacitors), or
get down into the socket pin or contact area. Applying a half-grain
of paste, squashing the heatsink into it, should show a "circle" of
paste, and the size of that circle will help you judge how big a dab
is needed to do the whole thing.

Cleaning kit, if you need it.

http://www.newegg.com/Product/Product.aspx?Item=N82E16835100010

Ceramique

http://www.newegg.com/Product/Product.aspx?Item=N82E16835100009

(You can download the MSDS, to see what they're made from, like boron nitride)

http://www.arcticsilver.com/PDF/thermcom/CMQ_MSDS_3.pdf

Sometimes, you can buy replacement materials, certified as being acceptable
to AMD or Intel, but most of us just use paste to do the job. You only
need to re-apply paste, if you notice the monitored CPU temperature
getting out of hand, in a few years time.

Paul

 

[MN]

Paul,
I did remove the heatsink/fan assy and checked the CPU for damage, etc; it
appeared OK. I then removed the CPU and reinserted it, using the ZIP locking
screw. I then replaced one of the 2 Gig DDR2 memory sticks, and applied
power and presssed the case power button. For the first time, I got a SINGLE
beep and saw the BIOS screen on the monitor. Unfortunately, it shutdown
after a few seconds. I repeated pressing the the case power button with the
same results: shutdown after a few seconds. Pressing DEL to enter BIOS setup
did no good; it shutdown too quickly. Since the processor was getting quite
warm, I stopped powering-up the mobo.

Later, I replaced the heatsink/fan assy and backplate. Then I repowered up
the mobo. It would not beep or display the BIOS screen on the monitor. I
removed the backplate (but keeping the the heatsink/fan assy on top of the
CPU) and powered-up the mobo; it again worked for a few seconds. After doing
this a few times, I noticed that the the heatsink/fan assy was getting quite
hot. It should be noted the fan NEVER rotated!

The quick shutdown probably occurred because the BIOS was set to shutdown on
specific detected error(s). (Shutdown Temperature exceeded, no drives
connected, etc.)

Although, I thought of spray painting the backplate and using it again, I am
considering getting a heatsink/fan assy that provides better cooling. (The
CPU got hot pretty quickly although it was not doing very much.).

Thanx for mentioning the Arctic Silver products. I will definitely need
them, now.

Since I will be ordering the Arctic Silver products, I might as well try to
find and then buy a more efficient heatsink/fan assy.

Marty

==============================================================

Paul replied