My power supply unit needs 2-3 hours to "warm up" before computer can be turned on!

[Jason Stacy]

I observed a strange problem with my computer. Once every approx.3 month I cannot turn on my computer
after shutdown. It seems to be dead.

After I plugged out power cable and plugged it in after 10 minutes and wait period of
approx 2-3 hours it works.

Does my Power supply unit device need a "warm up" period?

Its a be quiet BQT E5 model 400 W

J.

 

[Jerry]

No power supply should need time to 'warm up'. Replace it.

 

[Bryce]

I observed a strange problem with my computer. Once every
approx.3 month I cannot turn on my computer after
shutdown. It seems to be dead.

After I plugged out power cable and plugged it in after 10
minutes and wait period of approx 2-3 hours it works.

Does my Power supply unit device need a "warm up" period?

Its a be quiet BQT E5 model 400 W

J.

I have a hunch your motherboard isn't telling the power
supply to start up. You can narrow down the problem a bit
by disconnecting all of the power supply outputs (including
the big plug into the m/b). With mains power available to
the power supply, connect a jumper between the green wire
and black wire pins on that big plug you disconnected from
m/b. The power supply should start up, as indicated by it's
fan beginning to run. A bit of paper clip bent into a "U"
works well as the jumper. If the supply does not start, it
is the problem. Replace it.

My guess is the supply is OK. Possibly your CMOS backup
battery is in need of replacement. If it's really dead, the
BIOS may not be able to summon the smarts to send the start
command to the power supply ... but there's a +5VDC level
delivered to the m/b even when the power supply is off (but
still in touch with mains power). Maybe having this voltage
on for a while puts a bit of life back into the lithium cell
and then the BIOS re-awakens. There should be a diode that
blocks the power supply +5 from attempting to charge the
lithium cell, but diodes have small reverse leakage.

If you have a DC voltmeter, measure the lithium cell
voltage. Best to do this in-circuit: + probe on the +
battery side (usually up) and - probe on chassis ground.
Mains disconnected. You probably have a CR2032 cell, which
should read close to 3 VDC. If not, replace it.

Just my guess. Your money immediately refunded if this
doesn't help.

Bryce

 

[Andrew E.]

Whatever you do,do not follow the post by bryce.PC power supplys are
indeed "Switching Power Supplys",& those types of power supplies must
be tested under load..Running one w/o being "hooked up" will destroy the
unit.
As far as the problem(s) go,it sounds like a faulty switch.

 

[Peter Foldes]

And Andrew you are an idiot. Go get a life. It is not a faultyswitch but a faulty
PSU

 

[Stefan Patric]

I observed a strange problem with my computer. Once every approx.3 month
I cannot turn on my computer after shutdown. It seems to be dead.

Does the power supply fan run when you turn it on after a shutdown, even
if the computer doesn't?

After I plugged out power cable and plugged it in after 10 minutes and
wait period of approx 2-3 hours it works.

Could be a bad power supply. Replace it. If the problem goes away, that
was the problem.

Does my Power supply unit device need a "warm up" period?

No. Should be instant on.

Its a be quiet BQT E5 model 400 W

How old is it?


Stef