If my computer doesn't react at all...

[aakerman]

awww shucks! just bought a new cpu + mobo because the computer broke down a month ago.

Now there's already trouble again.. I was re-arranging my hard drives, and when I tried to boot up again, nothing happened when I pressed power on. Then I tried again ,and suddenly there was a flash of light inside my computer case.... a short circuit or something I presumed, and removed the PSU.

Installed a spare PSU I have. Nothing at all happens when I press power on.... can it be anything other than the PSU? How do I test this? Or has the motherboard been fried again, terminating the connection between the power-on button and the PSU?

HELP

 

[themisfit610]

Well, you need to test both power supplies to verify they both work.

Do this:
pull both power supplies, and connect them to something (fans preferably). Plug one at a time into the AC power, engage its power switch (if present), and then short the green wire and any black wire on the 20/24 pin power connector. Do this using a wire - spare ethernet cord dissected tends to work well - or whatever you have sitting around.

If the power supply powers up - that is, if the connected device powers up, or the power supply fan (if present) powers up, then your power supply at least works.

Verify that the supply you swapped in does work. If it does, then sorry - you hosed your motherboard and/or cpu and/or ram. RMA?

If the power supply does nothing, then there's still hope for your new components. Get a new PSU.

~MiSfit

 

[aakerman]

Okay thanks! I will try that.

If it turns out that the PSUs are fine (which I would venture to guess that they are, I mean.. two dead at the same time?) -
would it then be reasonable to assume that the motherboard is dead while the cpu is fine? Or can the cpu die too when the motherboard
goes?

 

[aakerman]

OK I just tried it.

I connected the PSU's, one by one, to a harddrive. Then I powered them up, and shorted the green and the black wire. In both cases, nothing happened at all.
Are you sure this means both PSUs are broken? Just wanna make sure before I go buy a new PSU

 

[bendixG15]

You could get a power supply tester ($13.00when I got mine)

Saved me lots of screwing around with PSU issues

 

[aakerman]

Hmm do you have a link?

 

[bendixG15]

Originally posted by: aakerman
Hmm do you have a link?

Good Luck.............

 

[Zepper]

Yes,

First check common things: power exists at wall outlet you are using (test it with a lamp or something) and that it's wired correctly (cheap wiring tester under $5.), PC's power cord plugged in tightly and all the way on both ends, voltage switch (if present) on PSU set to correct voltage, all necessary power cables from PSU plugged in: ATX, P4, PCI express, video card(s), whatever your setup requires.

Once the above is solid, try the following:

Boilerplate-01:
. Common causes of failure to boot (no video, no beeps) assuming PSU isn't totally dead:
1- RAM, CPU and/or AGP video card not seated properly, a bent pin or corrosion.
2- Drive data cable on upside down or only on half the pins or shifted a pin or two (usually Floppy or Zip drives).
3- CMOS needs to be cleared (AC power must usually be disconnected or . attempts to clear CMOS may fail) Unless your mobo does not use a power-off CMOS clear - check your mobo manual for specific info.
4- On some new mobos there is a CPU protection feature (esp. on Asus/Asrock Athlon/Socket A mobos) that will not allow the system to start if there is no fan (or a fan without a working speed sensor wire) connected to the CPU Fan power connector on the mobo (specifically marked "CPU Fan"). If you tried to start your machine without a fan properly connected, you have to attach a proper and working fan and clear the CMOS before it will boot.

.bh.