Steps to fix problem PC

[Znott]

Here's the problem. I boot the computer and it sounds like the HD's
start up. However, my keyboard does not power up. When I hit the
caps lock key, the light doesn't appear. which is odd. Also, my
monitor doesn't accept any input from the mouse or keyboard and stays
black..

Since the keyboard doesn't work, I can't go to the bios. As a test, I
disconnected both HD's and put in a bootable CD. Again, no keyboard
or monitor.

I used a keyboard from another computer and it doesn't work either.
So, what's my next step in troubleshooting the problem? Does this
sound like a motherboard problem and/or a a power supply issue?

Which steps should I take one-by-one to solve the problem?

Thx

 

[Mike T.]

Here's the problem. I boot the computer and it sounds like the HD's
start up. However, my keyboard does not power up. When I hit the
caps lock key, the light doesn't appear. which is odd. Also, my
monitor doesn't accept any input from the mouse or keyboard and stays
black..

Since the keyboard doesn't work, I can't go to the bios. As a test, I
disconnected both HD's and put in a bootable CD. Again, no keyboard
or monitor.

I used a keyboard from another computer and it doesn't work either.
So, what's my next step in troubleshooting the problem? Does this
sound like a motherboard problem and/or a a power supply issue?

Which steps should I take one-by-one to solve the problem?

Thx

It sounds like a bad power supply. It's either that or the motherboard.
But it's most likely the power supply. -Dave

 

[spodosaurus]

It sounds like a bad power supply. It's either that or the motherboard.
But it's most likely the power supply. -Dave

Maybe he should switch on the monitor as a first step.

--
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[Rod Speed]

Here's the problem. I boot the computer and it sounds like the HD's
start up. However, my keyboard does not power up. When I hit the
caps lock key, the light doesn't appear. which is odd. Also, my monitor
doesn't accept any input from the mouse or keyboard and stays black..

Since the keyboard doesn't work, I can't go to the bios.
As a test, I disconnected both HD's and put in a bootable CD.
Again, no keyboard or monitor.

Did it appear to be booting the CD ? Likely not.

I used a keyboard from another computer and it doesn't work either.
So, what's my next step in troubleshooting the problem?

Swap the power supply. Most likely the 5V rail isnt coming up
and that is why nothing happens with the keyboard. The 12V
rail is coming up and that is why the fans and hard drives spin up.

Does this sound like a motherboard problem and/or a a power supply issue?

Can be either, but its much more likely to be the power supply.

Which steps should I take one-by-one to solve the problem?

If you have a multimeter and know how to use one, measure
the rails from the power supply and if they are fine, check the
grey wire in the ATX connector, see if its coming up.
http://www.technick.net/public/code/cp_dpage.php?aiocp_dp=pinconmth_atx_power

If you dont have a multimeter, try another power supply.

If the power supply doesnt make any difference, its likely the motherboard
but it is worth trying it loose on the desktop before you replace it, you can
get a short to case if someone has left a loose screw floating around in
the case and that is the best test for that and the other shorts to case.

 

[Znott]

Wasn't the power supply. Just replaced it and still the same problem.
What tests, if any can I do with the motherboard?

ASUS P4P800-E Deluxe

 

[Paul]

Wasn't the power supply. Just replaced it and still the same problem.
What tests, if any can I do with the motherboard?

ASUS P4P800-E Deluxe

Do a visual inspection. Does your Southbridge look like the picture
at the top of this page ? If your Southbridge had a latchup failure,
the computer will no longer POST, and there won't be a beep at
power up. A theory is, that it is related to static (ESD) discharge
into the USB ports, which causes a rail-to-rail short where the
USB pads get power inside the Southbridge. The burn mark correlates
with the balls on the bottom of the chip that power the USB data
signals.

http://www.abxzone.com/forums/intel...-ich5r-chip-p4p800-ed.html?highlight=usb+port

Paul

 

[Bob M]

Here's the problem. I boot the computer and it sounds like the HD's
start up. However, my keyboard does not power up. When I hit the
caps lock key, the light doesn't appear. which is odd. Also, my
monitor doesn't accept any input from the mouse or keyboard and stays
black..

Since the keyboard doesn't work, I can't go to the bios. As a test, I
disconnected both HD's and put in a bootable CD. Again, no keyboard
or monitor.

I used a keyboard from another computer and it doesn't work either.
So, what's my next step in troubleshooting the problem? Does this
sound like a motherboard problem and/or a a power supply issue?

Which steps should I take one-by-one to solve the problem?

Thx

Is the keyboard USB or PS2? Try an adapter and use the opposite of what
you're using now.

Bob

 

[JAD]

you either lost(disabled) the PS/2 port or USB bios switch (legacy devices)
is set incorrectly
clear the CMOS and see what happens

 

[Znott]

Thanks, but Southbridge looks fine. Light on monitor is on. CPU
looks fine. Any other thoughts. Weird thing though. On my keyboard,
I press the number lock and my light on keyboard goes on but it almost
has a pulse at times. However, caps lock light will never go on.
AFter a few minutes of num lock light is on, it will freeze on
occasion and not go off again.

 

[Znott]

It's PS2 and I don't have an adapter. Do you really think it's still
worth it to try? The powered video card has power, fan is spinning,
but will not give a signal to monitor. Would a keyboard hooked up to
USB really change that?

 

[JAD]

It's PS2 and I don't have an adapter. Do you really think it's still
worth it to try? The powered video card has power, fan is spinning,
but will not give a signal to monitor. Would a keyboard hooked up to
USB really change that?

i assumed you were getting a signal................ different thing
altogether now....looks to be the mainboard

 

[Rod Speed]

you either lost(disabled) the PS/2 port

Shouldnt produce that keyboard led effect.

or USB bios switch (legacy devices) is set incorrectly

Or that, the most that should do is stop the keyboard
being seen by the bios at boot time, not the led effect,
particularly now he's posted more detail about the led effect.

 

[Rod Speed]

It's PS2 and I don't have an adapter. Do you really think it's still
worth it to try? The powered video card has power, fan is spinning,
but will not give a signal to monitor. Would a keyboard hooked up to
USB really change that?

Nope, it should POST and at most whine about the lack of a keyboard.

 

[Rod Speed]

Thanks, but Southbridge looks fine. Light on monitor is on. CPU
looks fine. Any other thoughts. Weird thing though. On my keyboard,
I press the number lock and my light on keyboard goes on but it almost
has a pulse at times. However, caps lock light will never go on.
AFter a few minutes of num lock light is on, it will freeze on
occasion and not go off again.

Check for bad caps on the motherboard.

 

[Znott]

Thanks. Afraid of that. I can switch that out once I fine another in
the area. Before I do that, how can I rule out that it's not the CPU?
I don't want to spend over a $100 on a M/B and find out it's something
else.

 

[Znott]

On, I did some research on what to look for in bad caps, but I only
found this site. I saw that the board was discolored just a bit in
these pictures and didn't see the same problem on my board, but maybe
I'm looking for the wrong thing.

http://www.motherboardrepair.com/images.do

 

[JAD]

Shouldnt produce that keyboard led effect.

I seemed to have missed the LED effect line...the fact that it 'doesn't'
light up?

 

[JAD]

Thanks. Afraid of that. I can switch that out once I fine another in
the area. Before I do that, how can I rule out that it's not the CPU?
I don't want to spend over a $100 on a M/B and find out it's something
else.

except for using it in another rig, nothing really. It is rarely the CPU
unless you burned it by poor cooling or running without a heatsink, and that
these days are rare instances.

 

[Rod Speed]

On, I did some research on what to look
for in bad caps, but I only found this site.

Sorry, the caps are usually blue or black plastic covered post
like things that stick up vertically from the motherboard surface.
The tops should be flat. If any have bulged or have leaked, thats
a bad cap and is the cause of the problem.

Asus has a 3 year warranty and should cover
that even if its outside that warranty now.

I saw that the board was discolored just a bit in
these pictures and didn't see the same problem on
my board, but maybe I'm looking for the wrong thing.

Yeah, its the caps themselves that usually show the problem.
http://www.motherboardrepair.com/images/BE6II_bad_caps_1.jpg

 

[JAD]

got it .... pulsing led....it would (should )point to the 5v rail being
inadequate, probably an anomaly of an overall failing board.