t2p4 power issue - help

  • Thread starter Thread starter lymantok
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lymantok

I have a p55/t2p4 board that fails to power up. I replaced the power
supply with a brand new power supply (same model) but the cpu fan
spins for 1/2 second when I apply power, then stops. Computer was
working fine last week, but exhibits this problem now. Any ideas
what's wrong or what to look for? Is the board toast?

Thanks!
 
I have a p55/t2p4 board that fails to power up. I replaced the power
supply with a brand new power supply (same model) but the cpu fan
spins for 1/2 second when I apply power, then stops. Computer was
working fine last week, but exhibits this problem now. Any ideas
what's wrong or what to look for? Is the board toast?
Click to expand...

No expert by a longshot, just tossing out some ideas.......

Does the power supply's own fan keep spinning?
(A board shorted to ground should turn the PS off, or blow the fuse)

How about when it's not plugged into the board?
(Lack of "load" from the board can also turn it off)

How's the power switch? Did the new PS come with a new switch?

Does the PS work with other boards (if you have any to test with)?

What kind of voltage do you get between black/yellow and black/red
on any of the power cables when the PS is turned on? How about when
not plugged into the board?

Have you tried slicing the board apart layer by layer and following the traces?
No, forget that one.... takes too long and makes a big mess. :)
 
Thanks for your ideas. Comments below. Any other thoughts?

No expert by a longshot, just tossing out some ideas.......

Does the power supply's own fan keep spinning?
(A board shorted to ground should turn the PS off, or blow the fuse)
Click to expand...

No. The old PS fan and the new PS do not come on at all connected to
the MB with or without a drive attached.
How about when it's not plugged into the board?
(Lack of "load" from the board can also turn it off)

How's the power switch? Did the new PS come with a new switch?
Click to expand...

Yes, new PS came with a switch. Old PS switch was ok also.
Does the PS work with other boards (if you have any to test with)?
Click to expand...

Unfortunately not. All my other boards are ATX.
What kind of voltage do you get between black/yellow and black/red
on any of the power cables when the PS is turned on? How about when
not plugged into the board?
Click to expand...

Old PS tested without load and the voltages were fine. I had it tested
by our hardware experts at work.
Have you tried slicing the board apart layer by layer and following the traces?
No, forget that one.... takes too long and makes a big mess. :)
Click to expand...

Hehe, nope. Sounds like a good excuse to get another mainboard!
 
I have a p55/t2p4 board that fails to power up. I replaced the power
supply with a brand new power supply (same model) but the cpu fan
spins for 1/2 second when I apply power, then stops. Computer was
working fine last week, but exhibits this problem now. Any ideas
what's wrong or what to look for? Is the board toast?

Thanks!
Click to expand...

You'll don't believe me, but I had the same problem and the cause was
that... I inverted the keyboard and mouse PS/2!!!!!!!!!!!!


bye
andr3a
 
No. The old PS fan and the new PS do not come on at all connected to
the MB with or without a drive attached.
Click to expand...
Old PS tested without load and the voltages were fine. I had it tested
by our hardware experts at work.
Click to expand...

So the old PS (and the new one?) both work fine when sitting on the bench
not plugged into anything at all; proper voltages, fan happily spinning away,
but plug the power leads into the MB, and *poof*, they both shut down?

Have you tried with the MB and PS completely out of the case, sitting
side-by-side on a piece of cardboard or something to eliminate any
short-to-ground possibility? (re: second line of this post)

Start with a totally bare board, no cards, no cables, nothing but the PS.
Try turning the PS on for just a couple of seconds.
If the fan keeps spinning, then add CPU, memory, keyboard, mouse,
video, etc... one at a time, testing for a couple of seconds with each new part.

(While testing a pile of old parts a while back, I came upon a video card that
would stop the boot process dead... no beeps, no HD spin-up, etc.)

Also, look closely to make sure a screw or some other tiny piece of metal
hasn't come loose, fallen onto the board, and short-circuited something.
 
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