Computer power supply

[[email protected]]

Just been handed back a computer that I earlier gave to friends that
were in need of one. It has a problem and I said I'd take a look at it
to see if it's something relatively easy to repair. I have never had
any reason to give a computers power supply a first look before
but at first glance I believe that is the problem. Correct me if I'm
wrong. Here's what I have:

A computer power light glows amber as soon as the line cord is plugged
in. There is no response when pushing or holding the power button.
I removed the power supply and started to check voltages. I only found
5.25 volts and 6.5 volts on two pins on the largest power plug that
goes to the mother board. The power supply fan never turned on.

I know somebody on this group can give me some advice on the
info I have given. I'll admit it. I'm lazy and would rather just ask
questions rather than dig in or research further. I don't even know if
all computer power supplies and plugs are standard. Any help would
be appreciated.

 

[[email protected]]

Just been handed back a computer that I earlier gave to friends that
were in need of one. It has a problem and I said I'd take a look at it
to see if it's something relatively easy to repair. I have never had
any reason to give a computers power supply a first look before
but at first glance I believe that is the problem. Correct me if I'm
wrong. Here's what I have:

A computer power light glows amber as soon as the line cord is plugged
in. There is no response when pushing or holding the power button.
I removed the power supply and started to check voltages. I only found
5.25 volts and 6.5 volts on two pins on the largest power plug that
goes to the mother board. The power supply fan never turned on.

I know somebody on this group can give me some advice on the
info I have given. I'll admit it. I'm lazy and would rather just ask
questions rather than dig in or research further. I don't even know if
all computer power supplies and plugs are standard. Any help would
be appreciated.

ATX by far the most common supply, often on sale _cheap_ and
connectors are standard. The best 'test' is to simply put in another
supply. They do fail occasionally especially if left on 24/7 and yours
sounds like a dead one.

I think everybody should have a spare especially if they have more
than 1 machine. Latest Fry's sale had a CoolerMaster 500 watt for $10
after the rebate so it won't break the bank to have one waiting.

 

[Marra]

Sounds like the 12 volts has died.

I would go for the new option too.

 

[James Sweet]

Just been handed back a computer that I earlier gave to friends that
were in need of one. It has a problem and I said I'd take a look at it
to see if it's something relatively easy to repair. I have never had
any reason to give a computers power supply a first look before
but at first glance I believe that is the problem. Correct me if I'm
wrong. Here's what I have:

A computer power light glows amber as soon as the line cord is plugged
in. There is no response when pushing or holding the power button.
I removed the power supply and started to check voltages. I only found
5.25 volts and 6.5 volts on two pins on the largest power plug that
goes to the mother board. The power supply fan never turned on.

I know somebody on this group can give me some advice on the
info I have given. I'll admit it. I'm lazy and would rather just ask
questions rather than dig in or research further. I don't even know if
all computer power supplies and plugs are standard. Any help would
be appreciated.

The most common problem I find is bad electrolytic capacitors. If it's a
standard ATX power supply I usually just replace them unless I need it
working in a rush.

 

[Dave Plowman (News)]

I know somebody on this group can give me some advice on the
info I have given. I'll admit it. I'm lazy and would rather just ask
questions rather than dig in or research further. I don't even know if
all computer power supplies and plugs are standard. Any help would
be appreciated.

http://www.helpwithpcs.com/courses/power-supply-basics-inc-pinouts.htm

In general they're not worth the bother of fixing as they're so cheap.
Unless you have the required spare parts lying around.

I'm not using a PC for this task and when the power supply failed on this
machine it was easier to adapt a PC one and fit it to this PS case than
repair it.

 

[[email protected]]

http://www.helpwithpcs.com/courses/power-supply-basics-inc-pinouts.htm

In general they're not worth the bother of fixing as they're so cheap.
Unless you have the required spare parts lying around.

I'm not using a PC for this task and when the power supply failed on this
machine it was easier to adapt a PC one and fit it to this PS case than
repair it.

Thanks to all. Yes the supply is dead. No 12 volts and the two sockets
readings at 5.25 and 6.5 volt are not correct.

The above link was helpful. I do have a question though from the link.
It says at the bottom of the page: "To power up an ATX or ATX-2 PSU
for testing, short pin 14 (PS_ON) with one of the grounds" I did this
and it made no difference. Does this mean on a good supply on the
bench that these pins have to connect to get all the various voltage
readings on the various pin outs?

 

[PeterD]

Thanks to all. Yes the supply is dead. No 12 volts and the two sockets
readings at 5.25 and 6.5 volt are not correct.

The above link was helpful. I do have a question though from the link.
It says at the bottom of the page: "To power up an ATX or ATX-2 PSU
for testing, short pin 14 (PS_ON) with one of the grounds" I did this
and it made no difference. Does this mean on a good supply on the
bench that these pins have to connect to get all the various voltage
readings on the various pin outs?

Yes, and you should also have a load on the power supply, some less
expensive supplies won't work correctly if not loaded.

 

[[email protected]]

Just been handed back a computer that I earlier gave to friends that
were in need of one. It has a problem and I said I'd take a look at it
to see if it's something relatively easy to repair. I have never had
any reason to give a computers power supply a first look before
but at first glance I believe that is the problem. Correct me if I'm
wrong. Here's what I have:

A computer power light glows amber as soon as the line cord is plugged
in. There is no response when pushing or holding the power button.
I removed the power supply and started to check voltages. I only found
5.25 volts and 6.5 volts on two pins on the largest power plug that
goes to the mother board. The power supply fan never turned on.

I know somebody on this group can give me some advice on the
info I have given. I'll admit it. I'm lazy and would rather just ask
questions rather than dig in or research further. I don't even know if
all computer power supplies and plugs are standard. Any help would
be appreciated.

If you plan on doing any computer h/w work, a p/s tester can be picked
up for <$20 and it really makes life easier.

 

[UCLAN]

If you plan on doing any computer h/w work, a p/s tester can be picked
up for <$20 and it really makes life easier.

http://www.pcpower.com/accessories/atx-power-supply-tester.html

 

[[email protected]]

Just like many other thingys,,, there is a big difference in Quality
computer power supplys.You buy cheap, you get cheap.
cuhulin

 

[[email protected]]

http://www.pcpower.com/accessories/atx-power-supply-tester.html

Personally, I prefer this one.
http://www.antec.com/us/productDetails.php?ProdID=77203

 

[w_tom]

It says at the bottom of the page: "To power up an ATX or ATX-2 PSU
for testing, short pin 14 (PS_ON) with one of the grounds" I did this
and it made no difference. Does this mean on a good supply on the
bench that these pins have to connect to get all the various voltage
readings on the various pin outs?

Unfortunately that test can only result in a probable result - a
'maybe'. Test that would have reported 'definitively good' or
'definitively bad' means disconnecting nothing, less labor, faster
testing, and numbers that mean the better informed will reply. Less
than two minutes using a 3.5 digit multimeter. A tool so 'complex'
and 'scary' as to be sold to K-mart, Radio Shack, Lowes, Tru-Value
Hardware, and Walmart customers.

Some good power supplies will not power when disconnected from
computer with pin 14 grounded. Some defective power supplies will
power when pin 14 is grounded. Some power supply problems may
actually be created by the power supply controller which is also not
found using a 'pin 14 grounded' test. Best way to identify a defect
faster and to obtain numbers so that others will provide useful
replies is summarized in "When your computer dies without
warning....." starting 6 Feb 2007 in the newsgroup alt.windows-xp
at:
http://tinyurl.com/yvf9vh

Power supply testers are also inconclusive as the 'pin 14 grounded'
test. Money for a power supply tester that will not provide a
definitive answer, that has no other purpose, and that still cannot
report a replacement supply as good? Same money is better spent on a
multimeter. A computer can still boot even if the new supply is
defective. Is a new supply good? Only useful answer means numbers
from that multimeter when a best load - your computer - is connected
to that new supply.

Grounding pin 14 can result in 'maybe the supply is defective'.
Power supply tester can only imply a good supply. 'Maybe' means the
supply and the rest of that 'power system' is still unknown. A
'system' has three possible states: definitively good, definitively
bad, and unknown. Only way to establish 'definitively something'
means numbers from a meter during maximum load.

 

[[email protected]]

my 3year old dell started having problems and it was the
power supply . it would turn on fine and the lite on front came on,but
it didnt compute right. lucas

http://www.minibite.com/america/malone.htm