help, please, with Compaq Presario power supply problem
 

Hi. I'm helping someone with a Compaq Presario 5320US desktop that
won't power on at all. The problem occured when the PC was moved from
one room to another. A previous tech told the owner to just go buy a
standard 350 watt power supply (which she did) and that he'd then
install it. This happened, apparently, without the tech even bothering
to do any actual troubleshooting -- plus, he was also apparently
ignorant of the fact that this Presario uses a non-standard proprietary
power supply. The owner can't get ahold of that guy now. So, the owner
says to me: can you fix it?

I can't even plug in the replacement standard power supply because the
motherboard has a 24-pin connector instead of the standard 20-pin.
Similarly, I can't use my quick-and-easy power supply tester because the
old power supply won't plug into that. I'd go ahead and start probing
with a DMM for proper voltages, but I'm under the impression that I'll
get nowhere with that if the power supply isn't already on and under
load. Finally, without a known good power supply, I can't even tell
whether the power supply was actually the problem, or whether it was
instead something else.

Any suggestions as to how to proceed? I did come across a web site that
sells 24-pin to 20-pin adapters, but does anyone know whether such
adapters even have a standard wiring pattern? Since the Compaq supply
is non-standard, how would I know whether the adapter would be wired
properly for it?

I found that the customer can buy an exact replacement part from the
HP/Compaq web site for $150, but doing so seems silly before we even
know where the problem lies.

Any help appreciated!

Jacques

"Jacques Clouseau" wrote in message
t...
Hi. I'm helping someone with a Compaq Presario 5320US desktop that
won't power on at all. The problem occured when the PC was moved from
one room to another. A previous tech told the owner to just go buy a
standard 350 watt power supply (which she did) and that he'd then
install it. This happened, apparently, without the tech even bothering
to do any actual troubleshooting -- plus, he was also apparently
ignorant of the fact that this Presario uses a non-standard proprietary
power supply. The owner can't get ahold of that guy now. So, the owner
says to me: can you fix it?

I can't even plug in the replacement standard power supply because the
motherboard has a 24-pin connector instead of the standard 20-pin.
Similarly, I can't use my quick-and-easy power supply tester because the
old power supply won't plug into that. I'd go ahead and start probing
with a DMM for proper voltages, but I'm under the impression that I'll
get nowhere with that if the power supply isn't already on and under
load. Finally, without a known good power supply, I can't even tell
whether the power supply was actually the problem, or whether it was
instead something else.

Any suggestions as to how to proceed? I did come across a web site that
sells 24-pin to 20-pin adapters, but does anyone know whether such
adapters even have a standard wiring pattern? Since the Compaq supply
is non-standard, how would I know whether the adapter would be wired
properly for it?

I found that the customer can buy an exact replacement part from the
HP/Compaq web site for $150, but doing so seems silly before we even
know where the problem lies.

If no power at all it could be the power switch. Check that with your ohm
meter. If that's ok, check for power on any of the power supply molex
connectors. If no power there, it's the PS.
You could use and ATX PS and rewire the compaq connectors with a little help
from google or just move everything except the MB over to a new case/PS for
$100.

Have you checked the line cord?

Jacques Clouseau wrote:
Hi. I'm helping someone with a Compaq Presario 5320US desktop that
won't power on at all. The problem occured when the PC was moved from
one room to another. A previous tech told the owner to just go buy a
standard 350 watt power supply (which she did) and that he'd then
install it. This happened, apparently, without the tech even
bothering to do any actual troubleshooting -- plus, he was also
apparently ignorant of the fact that this Presario uses a
non-standard proprietary power supply. The owner can't get ahold of
that guy now. So, the owner says to me: can you fix it?

I can't even plug in the replacement standard power supply because the
motherboard has a 24-pin connector instead of the standard 20-pin.
Similarly, I can't use my quick-and-easy power supply tester because
the old power supply won't plug into that. I'd go ahead and start
probing with a DMM for proper voltages, but I'm under the impression
that I'll get nowhere with that if the power supply isn't already on
and under load. Finally, without a known good power supply, I can't
even tell whether the power supply was actually the problem, or
whether it was instead something else.

Any suggestions as to how to proceed? I did come across a web site
that sells 24-pin to 20-pin adapters, but does anyone know whether
such adapters even have a standard wiring pattern? Since the Compaq
supply is non-standard, how would I know whether the adapter would be
wired properly for it?

I found that the customer can buy an exact replacement part from the
HP/Compaq web site for $150, but doing so seems silly before we even
know where the problem lies.

Any help appreciated!

Jacques

Is there an on/off switch on the back of the power supply?
Is the 110V/220V switch on the back of the power supply in the proper
postion?

In article ,
says...
Hi. I'm helping someone with a Compaq Presario 5320US desktop that
won't power on at all. The problem occured when the PC was moved from
one room to another. A previous tech told the owner to just go buy a
standard 350 watt power supply (which she did) and that he'd then
install it. This happened, apparently, without the tech even bothering
to do any actual troubleshooting -- plus, he was also apparently
ignorant of the fact that this Presario uses a non-standard proprietary
power supply. The owner can't get ahold of that guy now. So, the owner
says to me: can you fix it?

I can't even plug in the replacement standard power supply because the
motherboard has a 24-pin connector instead of the standard 20-pin.
Similarly, I can't use my quick-and-easy power supply tester because the
old power supply won't plug into that. I'd go ahead and start probing
with a DMM for proper voltages, but I'm under the impression that I'll
get nowhere with that if the power supply isn't already on and under
load. Finally, without a known good power supply, I can't even tell
whether the power supply was actually the problem, or whether it was
instead something else.

Any suggestions as to how to proceed? I did come across a web site that
sells 24-pin to 20-pin adapters, but does anyone know whether such
adapters even have a standard wiring pattern? Since the Compaq supply
is non-standard, how would I know whether the adapter would be wired
properly for it?

I found that the customer can buy an exact replacement part from the
HP/Compaq web site for $150, but doing so seems silly before we even
know where the problem lies.

Any help appreciated!

Jacques

Martik, Icee -- Thanks for the suggestions, which I'll consider. I do
know that there isn't a voltage switch on the back of the Compaq power
supply, so that's not it.

Jacques

I can tell you from experience that the power supply is so proprietary that
the 24 pin connectors won't work,and it's very doubtful that you could
rewire a standard unit to work.Replacements can be had for much less than
Compaq's going price at various parts sites,if you look around.
"Jacques Clouseau" wrote in message
t...
Hi. I'm helping someone with a Compaq Presario 5320US desktop that
won't power on at all. The problem occured when the PC was moved from
one room to another. A previous tech told the owner to just go buy a
standard 350 watt power supply (which she did) and that he'd then
install it. This happened, apparently, without the tech even bothering
to do any actual troubleshooting -- plus, he was also apparently
ignorant of the fact that this Presario uses a non-standard proprietary
power supply. The owner can't get ahold of that guy now. So, the owner
says to me: can you fix it?

I can't even plug in the replacement standard power supply because the
motherboard has a 24-pin connector instead of the standard 20-pin.
Similarly, I can't use my quick-and-easy power supply tester because the
old power supply won't plug into that. I'd go ahead and start probing
with a DMM for proper voltages, but I'm under the impression that I'll
get nowhere with that if the power supply isn't already on and under
load. Finally, without a known good power supply, I can't even tell
whether the power supply was actually the problem, or whether it was
instead something else.

Any suggestions as to how to proceed? I did come across a web site that
sells 24-pin to 20-pin adapters, but does anyone know whether such
adapters even have a standard wiring pattern? Since the Compaq supply
is non-standard, how would I know whether the adapter would be wired
properly for it?

I found that the customer can buy an exact replacement part from the
HP/Compaq web site for $150, but doing so seems silly before we even
know where the problem lies.

Any help appreciated!

Jacques

In article ,
says...
I can tell you from experience that the power supply is so proprietary that
the 24 pin connectors won't work,and it's very doubtful that you could
rewire a standard unit to work.Replacements can be had for much less than
Compaq's going price at various parts sites,if you look around.
"Jacques Clouseau" wrote in message
t...

Thank you for the information -- that's exactly what I needed to know.

Now I just need a way to diagnose whether the problem's the power supply
or something else.

Thanks,

Jacques

I would suggest that you start by disconnecting everything, including
the mobo from the supply.
Then hook up just one hard drive and check the 5 and 12 volt lines at
the ends of a
drive power connector. Other voltages can be checked by following the
below
code; most people followed the standard color codes, even if the
supplies were
non standard;
3.3V=Orange, 5V=Red, 12V=Yellow, -12V=Blue, -5V=White(may not be
present)
Common=Black, 5Vstandby=Purple. PSOn is usually Green. PwrOK=Gray
You will have to ground the on to common, green to Black, to turn it on.
If
it passes this test then hook up just the mobo, with no cards or memory
and recheck
Keep adding things ONE at a time until it fails.




"Jacques Clouseau" wrote in message
t...
In article ,

says...
I can tell you from experience that the power supply is so
proprietary that
the 24 pin connectors won't work,and it's very doubtful that you
could
rewire a standard unit to work.Replacements can be had for much less
than
Compaq's going price at various parts sites,if you look around.
"Jacques Clouseau" wrote in message
t...

Thank you for the information -- that's exactly what I needed to know.

Now I just need a way to diagnose whether the problem's the power
supply
or something else.

Thanks,

Jacques