Cold-sensitive power supply?

[Norman Swartz]

My computer is in a room that is kept at 68F (20C)during the day when I
use the computer, and at 50F (10C) overnight when I am not using it.

Very often when I try to boot up the computer in the morning (while it is
still cold), the fan on the power supply spins for a second or two, and
then the computer shuts down. Sometimes I have to try booting the
computer as many as ten times before it powers up correctly.

I have tried leaving the computer in standby mode overnight, but
oftentimes this doesn't solve the problem.

Should I be looking to replace the power supply? I am handy with a
soldering gun, and I know how to handle electrolytic capacitors. Should
I open the power supply and look for a cold-soldered connection or a
hairline fracture on a board? Any other likely source for the problem?

Thanks.

 

[jimover]

I would say yes, replace the power supply. Something is not right. Why
are you keeping that room that cold anyhow? Having your computer room
between 65-70F would work great all the time. Getting below that you
can cause humidity problems.

I don't know what kind of hardware you have in there, but you might not
have enough power if it is shutting down at boot. PC's require the most
power when first starting up. I would suggest getting an Antec power
supply and at least 430 Watts if not more. Get more than you have now.

 

[Rod Speed]

My computer is in a room that is kept at 68F (20C)during the day when
I use the computer, and at 50F (10C) overnight when I am not using it.

Very often when I try to boot up the computer in the morning (while it
is still cold), the fan on the power supply spins for a second or two,
and then the computer shuts down. Sometimes I have to try booting
the computer as many as ten times before it powers up correctly.

I have tried leaving the computer in standby mode
overnight, but oftentimes this doesn't solve the problem.

If you dont turn it off overnight and just turn the monitor off
overnight, that should fix the problem, albeit with more power use.

Should I be looking to replace the power supply?

Those symptoms can be due to that and its certainly cheaper
to try that than the other alternatives except leaving it on.

I am handy with a soldering gun,

You shouldnt use one of those in a PC.

and I know how to handle electrolytic capacitors.

Should I open the power supply and look for a cold-soldered
connection or a hairline fracture on a board?

Not usually worth it given what power supplys cost.

Any other likely source for the problem?

Could be bad caps in the power supply or motherboard.
The tops should be flat and any that have bulged or have
leaked are bad and replacing those should fix the problem.

 

[kony]

My computer is in a room that is kept at 68F (20C)during the day when I
use the computer, and at 50F (10C) overnight when I am not using it.

It might not hurt to describe this computer, all major
parts. Some parts are known to be marginal and have
problems with cold temps (like certain Geforce 4 TI video
cards) due to their capacitors, and it's conceivable other
parts with caps could have a similar problem.

I'm suggesting that it's probably either caps, or the other
obvious factor you begin to mention below, mechanical
intermittent contacts whether they be cold solder joints,
crack(s) in some part, or very poor mechanical connectors.

As for the mechanical connectors, that is a bit easier, you
can remove, inspect, and reinstall the parts taking extra
care to make sure everything is seated well and with cards,
that they're linked up as perfectly as possible with the
card slots (some cases might be off-spec or motherboard
could be mounted a bit to the side of the mounting hole and
combination of off-mounted parts might need adjustments.
Normally they would not but normally a system will start at
50F, so,

Very often when I try to boot up the computer in the morning (while it is
still cold), the fan on the power supply spins for a second or two, and
then the computer shuts down. Sometimes I have to try booting the
computer as many as ten times before it powers up correctly.

I'd suspect PSU more than anything else due to it shutting
down.

I have tried leaving the computer in standby mode overnight, but
oftentimes this doesn't solve the problem.

Should I be looking to replace the power supply? I am handy with a
soldering gun, and I know how to handle electrolytic capacitors. Should
I open the power supply and look for a cold-soldered connection or a
hairline fracture on a board? Any other likely source for the problem?

Describe the PSU make, model, wattage, maybe we can asses in
the context of the system description asked for above. It
could be that it merely needs some capacitors replaced, but
we don't even know if it's worthwhile to do that or even
hold old it is (as relating to lifespan).

You could also inspect the PSU but I doubt it's fractured or
has a cold solder joint, though perhaps if it had poor
quality or a manufacturing defect these things are more
likely, particularly with lower quality PSU right after the
switch to the RoHS, lead-free solder in manufacturing. Had
it performed reasonably last winter / temps with this system
or is it the first time this scenario is presenting itself?
Also inspect the capacitors, they may be failing and merely
showing first signs of instability that would get worse- at
the coldest temps first.

If you had a spare PSU, I'd suggest trying it with the
system to save a bit of time tearing apart the old one so
it's more clear whether it's the problem. Usually when I
come upon situations like you describe I'll just swap in a
different PSU with no plans to return the original to the
system, instead it'll be checked and fixed (if warranted)
then put to another use instead of uninstalling the other
PSU and reinstalling it again.

 

[DaveW]

IF you read the environmental specifications for power supplies, harddrives,
etc. you will see that they are NOT designed to run until they have warmed
up beyond 50 F to varying degrees. The power supply is fine.