Power Supply

[Jeff Houston]

This might seem similar to Ken Halls question a few days back but here goes.
I have a system here that was running fine but then it started acting up and
freezing up pretty bad now when I turn the power on to boot up it wont do
anything. The power button comes on but that is the only thing that does.
The fan on the power supply is not coming on and no other lights are coming
on i.e. CD or floppy lights. Nothing is coming on except the power button
light but it is not amber it is bright green. anyone got any ideas what
would cause this? I am going to get me a power supply tester today but in
meantime any suggestions are appreciated.

 

[Bob M]

This might seem similar to Ken Halls question a few days back but here goes.
I have a system here that was running fine but then it started acting up and
freezing up pretty bad now when I turn the power on to boot up it wont do
anything. The power button comes on but that is the only thing that does.
The fan on the power supply is not coming on and no other lights are coming
on i.e. CD or floppy lights. Nothing is coming on except the power button
light but it is not amber it is bright green. anyone got any ideas what
would cause this? I am going to get me a power supply tester today but in
meantime any suggestions are appreciated.

Check for leaking or blown caps on the motherboard.

Bob

 

[w_tom]

The power supply tester costs about same as a 3.5 digit
multimeter, takes longer to test, AND cannot detect many power
supply problems. Your fastest solution (which also teaches
you how the PSU system works) is in the post entitled "PSU
Failing or what?" on 12 Jan 2005 in this newsgroup
alt.comp.hardware.pc-hardware.

Yes it could be caps on the motherboard, or caps in the
power supply, or a failing regulator, or a defective power
cable, or a bad signal from the motherboard power supply
controller, or a sticky power switch, or ... So replace them
all. OR find out which is defective doing a procedure that
takes far longer to read than it does to perform. Heart of the
solution is a 3.5 digit multimeter. A tool even used by
junior high school science students. So ubiquitous and easy
to use as to be sold in Sears, Home Depot, Lowes, and Radio
Shack.

First get facts. Then fix what was found defective. It
could be this and it could be that is the sin called
'shotgunning'.

 

[doS]

damn good post.

The power supply tester costs about same as a 3.5 digit
multimeter, takes longer to test, AND cannot detect many power
supply problems. Your fastest solution (which also teaches
you how the PSU system works) is in the post entitled "PSU
Failing or what?" on 12 Jan 2005 in this newsgroup
alt.comp.hardware.pc-hardware.

Yes it could be caps on the motherboard, or caps in the
power supply, or a failing regulator, or a defective power
cable, or a bad signal from the motherboard power supply
controller, or a sticky power switch, or ... So replace them
all. OR find out which is defective doing a procedure that
takes far longer to read than it does to perform. Heart of the
solution is a 3.5 digit multimeter. A tool even used by
junior high school science students. So ubiquitous and easy
to use as to be sold in Sears, Home Depot, Lowes, and Radio
Shack.

First get facts. Then fix what was found defective. It
could be this and it could be that is the sin called
'shotgunning'.

 

[larry moe 'n curly]

I have a system here that was running fine but then it started acting up and
freezing up pretty bad now when I turn the power on to boot up it wont do
anything. The power button comes on but that is the only thing that does.
The fan on the power supply is not coming on and no other lights are coming
on i.e. CD or floppy lights. Nothing is coming on except the power button
light but it is not amber it is bright green.
I am going to get me a power supply tester today

Don't waste your money on a power supply tester when a digital
multimeter and paperclip are cheaper and better. I had a PSU tester
tell me that one PSU was fine even though its +12V rail put out only
10.xxV, which was so low that the hard drive wouldn't even spin. OTOH
even a $3 Harbor Freight digital multimeter will be accurate to 1% and
can test lots of things in addition to power supplies, like the CMOS
battery and the CPU Vcore voltage.

The paperclip connects between the green wire on the 20-pin ATX
connector (pin 14) and any black wire, like pin 13 or 15 next to it.
The black meter lead goes to any black wire on any connector, while the
red lead goes to the voltage rail you want to measure -- red wire for
+5V, yellow for +12V, orange for +3.3V, purple wire for +5V standby
(puts out voltage even without the paperclip in place). Some PSUs
don't put out accurate voltages without a load connected to them, such
as a hard drive or a 5-10 ohm resistor rated for at least 10 watts and
connected between any red and black wires.

 

[Jeff Houston]

Ok I will check into some of these things but as for that post I cant get
into that newsgroup it is not showing up on my list even though I updated it
just now. Could someone copy this for me and send it to me please? It would
be much appreciated.

 

[Jeff Houston]

P.S.
I just took a peek at the motherboard and there are three capacitors that
are different from the rest and those three seem to be leaking but I don't
think they are bulging or blown for sure. But I do think they are leaking.
The rest of the capacitors seem fine its just these three and they are all
three side by side by side.