Computer won't start - dead mobo? HELP

P

prasvt

Gawd
Joined
Dec 8, 2005
Messages
557
Hey guys...having some problems with one of my computers. Here are the specs:

C2D e2200
Asus P5N-E SLI motherboard
Rosewill 500W PSU
GeForce 7300GT PCI-E
2 x Seagate SATA 250GB in Raid 0
1 x 180GB Samsung IDE
NEC DVD/RW
2 x 1GB G.Skill DDR2 800

Okay, so the last time the computer was used was Friday. My sis printed out some maps for her San Diego trip and then I guess turned the machine off. Meanwhile, I was in the midst of my water cooling install, and decided to check something online. But, when I hit the power button, nothing happened. I reset the CMOS, and tried again. This time, the PSU + case fans started spinning up for less than a second before everything turned off. I removed the memory and tried again, and then each stick alone ...same thing. Then I decided to test the PSU ..so I shorted those two pins out and turned it on - all the case fans worked. Now...when the PSU is connected to the motherboard, the LEDs on the board are on (not sure what they refer to...but looks like power's getting to the board).

Now...I don't have an extra socket 775 cpu laying around (just sold my e6420) so I'm not sure whether the motherboard has died or the cpu. The e2200 was running at 2.8 w/ relatively low voltage (<1.4V I think)...I had throttled back on overclocking since the machine isn't really used for much more than printing and family usage.

I do have another motherboard - an MSI P6N SLI-FI. Like the Asus board, it's an nvidia 650i board.

Since I'm relatively sure the PSU is okay ..should I stick the CPU in the other board and see what happens? I'm guessing if the computer won't start w/ either board, the CPU may have died.

Otherwise it's the mobo right? Any suggestions on what I should check for would be very helpful. Thanks!
 
No beeps. I just switched everything to the P6N SLI-FI board and the exact same thing happened. I did hear tiny hum from the PSU though...

Technically the computer should boot and beep regardless of whether the cpu is in there or not right? I have a feeling it IS the PSU.

Unfortunately I don't have any backup psus on me...I'd have to go buy one and check. The exact same thing happened w/ the other board...reset the cmos and the board will attempt to power up for < 1 sec.

Kind of lost at this point.
 
Id buy a cheap dvom meter 10-15 bucks and do a pin out of the voltages on start...this will kinda tell you if correct voltage is going to the board...ad really suspect the board but the cpu isnt out of the question.....
 
Are you sure that you're not getting the emergency power supply trip mechanism to turn off the power supply so it doesn't short itself out? I had a very similar situation where my PSU would come on for a couple seconds and everything would spin up and then it would shut itself off to protect itself from damage. I know this doesn't horribly narrow it down b/c of one faulty component along the line could do it, but for me it was just a loose power connector, but you could use a system of elimination to try to find it.
 
It might be an emergency trip mechanism ..when you say faulty component, do you mean something plugged in, like the video card, ram, etc., or do you mean one of the power lines from the PSU?
 
i had this same thing happen, PSU works great in any other computer, but if i had it on this gigabyte p35 ds3l with a 2.8 p4 d, it would power on, then off...all it would do

So i moved the cpu fan power connector to another one, and vwala it powered up just fine.

come to find out the dang fan was a POS, i replaced the cooler with another one and it worked just fine on the CPU Fan spot

Not sure if it would the same in this case, but it sounds alot like what happend to me.

Just try moving the cpu fan connector to another plug, and unplug ANY non vital things to get it to boot, like all hard drives/roms, fans (except the cpu fan ofcoarse), just have the vital things to get into the bios with!

hope that helps :)
 
Okay I'll check the cpu fan connector - that's one thing I didn't disconnect. I'll report back in a few min.
 
Wait...when I moved the cpu over to the MSI board, I changed coolers from the stock intel hsf to the tuniq tower 120 ....so actually I guess that's not it.
 
ah, if thats the case i too would point to the PSU going down.

I myself need to get a better PSU for the DS3L (rosewill 350w lol) good enough for testing, and held up my old computer quite well!
 
Well I suppose if I really wanted to, I could hook up the psu to my sig machine...but that's a royal pain in the ass..esp w/ the water cooling setup in the case...I prob need to pick up a psu tester.

It just seems unlikely that the cpu would die. I didn't even push it...though it was on stock cooling, it had AS5 on it and the computer room is the coolest room in the house..

I think after this weekend's activities (installing the wc setup, installing 2 ceiling fans), my patience for troubleshooting is shot a bit.

Plus testing the same cpu and same psu (ie. the same possible suspects) on two diff mobos seems kind of pointless aside form ruling out the mobo as a problem.
 
if not ...could you guys suggest a decent psu for a non-gaming rig? I thought about giving that machine my 600W OCZ but hell after 2 years, it's still $110 on newegg and people are still buying it. So, no OCZ for that machine. Something 500W w/ good volt readings on the +12V and build quality.
 
Hmm yeah those two were on my short list. The Antec is 80plus certified too. Thanks!
 
I don't see a 8-pin 12V connector on the Antec ... would I use a 4pin to 8 pin converter? Both my p35 board and the msi board have 8pin connectors. the Asus board has a 4pin one. Never been quite sure about that.
 
AH, it wasn't the CPU, mobo, or PSU! It was the F'ing cheapo XFX 7300GT video card! I was testing the system out of the case and video card got dislodged from the pci-e slot, and voila the system turned on! I have a feeling it burned out or something. The fan on the cheapo heatsink was rattling when I bought it so I disconnected it (that and it would get stuck).
 
I was about to suggest pulling your cards. The only reason I know is because my sound card was dislodged and fried a few weeks ago and I had the same problem ;) Any time I have power problems like that I reset the CMOS, disconnect everything, and boot. If that doesn't work it's always worth pulling the motherboard and booting with it outside of the case. I've seen motherboards short somehow by not seating in the case properly. PSU's are the least likely to go out IMO so I always assume it's something else first. Glad you fixed the problem.
 
prasvt said:
AH, it wasn't the CPU, mobo, or PSU! It was the F'ing cheapo XFX 7300GT video card! I was testing the system out of the case and video card got dislodged from the pci-e slot, and voila the system turned on! I have a feeling it burned out or something. The fan on the cheapo heatsink was rattling when I bought it so I disconnected it (that and it would get stuck).
Click to expand...

dude, the exact same thing happened to me when i first installed in my new case in my sig, took me over a week to figure out what the problem was. then i had the same problem when i first installed and ran sli too. good thing you found the problem, i know the feeling when you are chasing those ghosts in the case....
 
Yeah I don't know why it didn't occur to me to just take out the cards..maybe I was too fixated on the psu lol. Anyway I'm gonna replace it with an HD3450 immediately. I wish I'd figured that out before I switched motherboards - both the Asus and MSI boards are 650i sli boards so hopefully I won't need to reformat. Well anyway, I like the MSI board + bios better. Plus, now this sucker's gonna have the Tuniq Tower so I can get a little more aggressive w/ the OC ;)

Thank you guys for your help by the way. It helps to get some fresh ideas regardless of how many times we try to fix stuff.
 
"chasing those ghosts" - lol. Exactly...I kind of got lucky. This could have become a much more expensive problem...reminds of when the X-fi sound cards (extrememusic model) had issues w/ nvidia chipsets...I rma'd 2 perfectly good asus p5b boards and finally returned one, then bought the P6N SLI-FI - Only to realize that the sound card was the problem - then sent in the x-fi to have it's firmware upgraded, got it back..and I'm guessing they didn't sh*t to it b/c the same problem occurred. Finally I got fed up, gave that x-fi to my roommate for xmas, and bought a x-fi fatality (which apparently had no compatibility issues).
 
You must log in or register to reply here.
Back
Top