Computer does not POST (no beep), No Video, Tried everything!

JohnnyJohnson17

Junior Member
Jun 21, 2011
4
0
0
Hi, before I start, here are my computer specs:

Motherboard: GIGABYTE GA-P55-UD3R
CPU: Intel i5-750
RAM: OCZ PC3-12800 Obsidian 4GB Dual Channel Kit
PSU: OCZ 500 Watt
Video Card: GIGABYTE GV-R455D3-512I
OS: Windows 7 64-bit


I built this system about 1.5 years ago and it hasn't had any problems until now.

What happened was about 4 weeks ago I opened up the heatsink and replaced the thermal paste on the CPU with artic silver 5 because I noticed that the CPU was running hot (windows 7 kept on running some networking file whenever idle that caused like 90% CPU consumption and I couldn't turn it off, only not be idle...temps were like 38 C to 66 C intermittently). After replacing the thermal paste, the computer ran well for 3-4 weeks. Then I turned on the computer a couple days ago and while I was browsing on the internet it just rebooted.

After it rebooted, I got a black screen on my monitor and nothing showed up.

Since then, whenever I try to boot, there is no POST, no beeps, and a black screen.

So far, this is what I have tried. I have removed/reseated the RAM, I have tested the PSU with the multimeter, I have built the system outside of the case to check for shorts, I have tried to boot the system with no RAM, no video card, I have taken off the heatsink and re-seated the CPU, and I have reset the CMOS manually. Still, all I get is no POST, no beeps, nothing.

The speaker was working up until the last known good boot a couple days ago so I don't think that the speaker is the problem.

When the computer powers up, the hard drive powers with it, the fans spin, and the lights come on in the motherboard and on the LED in the front.

One thing I did notice is that even though the CPU fan spins, it doesn't seem like it spins fast enough and the heatsink on the CPU never gets hot.

I specifically tested the CPU 8-pin 12 volt power source from the PSU.

I have filed the question with GIGABYTE but haven't received a response yet.

Maybe you guys can help me because I'm really out of ideas and disappointed :(


THANKS
 

nboy22

Diamond Member
Jul 18, 2002
3,304
1
81
Sounds to me like the motherboard might be toast, don't really know what else you could try other than trying a different video card and other odds and ends. Like you said though, there's no beeps which is strange. The only time I've ever had something like that was when one of my motherboards got shocked by static electricity. It ruined the whole motherboard to the point where it wouldn't start up, RMA'd it because it was a new machine.
 

wsaenotsock

Member
Jul 20, 2010
90
0
66
Did you check all the voltages from the psu?

Sounds like possible motherboard failure. Also make sure none of the AS5 leaked off.
 

denis280

Diamond Member
Jan 16, 2011
3,434
9
81
you replaced the thermal paste because it was running kind of hot.well i would try replacing the cpu. with a bad cpu there is no beep and no post.
 

JohnnyJohnson17

Junior Member
Jun 21, 2011
4
0
0
you replaced the thermal paste because it was running kind of hot.well i would try replacing the cpu. with a bad cpu there is no beep and no post.

When I say hot I mean that it ran from 38 C to 66 C.

Also, where do I check if the thermal paste got anywhere else...I think I already did that and in other posts people keep saying that is gets onto the pins but I'm not sure how that is possible...mine looks like it is only on the top of the chip itself.


Thanks
 

denis280

Diamond Member
Jan 16, 2011
3,434
9
81
when you put everything back together(CPU)did you look to see if you d'indnt bend one pin on the cpu.
 

JohnnyJohnson17

Junior Member
Jun 21, 2011
4
0
0
when you put everything back together(CPU)did you look to see if you d'indnt bend one pin on the cpu.

Well I never removed the CPU from the mobo when I was applying the thermal paste. Even after applying the paste, it still worked well for almost a month so I'm not sure how it would go bad all of a sudden. I'll check it in the AM and see if maybe I pressed down too hard, thanks.
 

denis280

Diamond Member
Jan 16, 2011
3,434
9
81
ok then the only things left is the cpu was going and now it is gone.i would doubt the mobo.
 

airush

Junior Member
Aug 1, 2013
2
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Ok to diagnose this issue you need to start with a Blank MB. To achieve post check boot you need the bare minim 1x ram stick, GPU, and PC-speaker, PWS(removed all other RAM, PCI Cards and add-ons. Clear COSMOS (Check manufactures MB manual for instructions)
Start system If no beep after 12sec, then replace power supply if buying another,,, ensure to update to suitable wattage to run your whole system under-load.
Start your system, check post-check beep or BEEPS. Refer to you MB manufactures manual to determine Beep code.
I've had a few DIY projects and found that usually just be turning power supply off the pull all PCI-cards,add-on cars and all ram out. Power on 30sec Power off system and switch off power supply. Plug everything back in and bingo all good.
If symptoms persist check\change Power Supply.
If no Beep then check\change MB
 
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airush

Junior Member
Aug 1, 2013
2
0
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And YES you need to uses paste,,,Especially when CPU is under load and need to transfer heat effectively from the CPU to brevet CPU after-burn for example :hmm: