Question Pc will not Power on, after a simple thermal paste change.

Jun 27, 2021
6
1
15
0
Parts:
CPU: i7-6700k
Mobo: Asus maximus VII Extreme
Power supply: EVGA 1000 P2
Dram: 4x4gb Corsair
GPU: SLI 980 TI
harddrive: m.2 samsung 950 pro
CPU cooler: corsair AIO h100i

My pc that I built myself 6 years ago decided to stop turning on after I changed the thermal paste one morning.

I had notice the idle and load temperature was a bit higher then what it was a few years ago. I figure it might be the thermal paste drying out, after all its been 6 years. So i turn off my PC, hit the power supply switch, then unplugged the cord and went to sleep. The next morning i lifted the computer and gentlely placed it on my bed to be operated by. I took the AiO cooler off, unlatched the cpu, cleaned the old artic 5 silver off the cooler and the cpu carefully with some 99% isopropyl alchohol. Gently drop the cpu back into the LGA socket and placed the ZIP latch down. Then the cooler went back on making sure not to overtighen it. Everything went smoothly and i closed the front case panel and put it back on the desk to be pluged in. With the cord back in, and the switch on the PSU back on "I", i could see the LED on my motherboard glow. However when i went to start the computer.... the power button did nothing. No sound was coming from computer, no Beep from the speaker to tell me it started POST. I was in panic mode. I decided to try the power and reset button on the motherboard itself, still nothing, i try to jump the power SW to start it, still nothing. No sound, no life.

I have since taken the motherboard out of the case and beardboarded the build on a cardboard box. With only the CPU, cpu cooler, 1 stick of dram in slot 1, and of course the power supply. Still no sign of life from my baby.

Below is a list of everything ive tried to diagnose the issue.

-triple check the CPU socket for bent pins, none from what i can tell. I even got a magnifying glass and checked everything from a low eye level. No thermal paste either, super clean, not a spec of dust.

- checked the CPU bottom side for Thermal paste, again its clean.

-checked the CPU coolers fan are plugged in.

-quadruple checked the 24 pin mobo power cable and the 8 pin CPU power. Both are in nice and tight, cant even fit my nails into the gap.


- reseated the CPU multiple times

-reseated the Dram

-removed and replaced the CMOS battery.

-cleared CMOS with the CLR CMOS button on the motherboard as well as the battery removal method.

-cleared any static charge left in the system by turning off PSU and holding the power button for 30 seconds.

-jumped the PSU with a papwr clippp and tested PSU for power problems using a Multimeter at the 24 pin connector plug. All voltage values 3.3/5/12v came back within a +1-3% above of the expect value. This means my PSU is good. condition and outputting the right voltage to everything.

Having breadboarded the build and proving the PSU is good, is there anything else i can do aside from swaping out the CPU and Motherboard? Something i want to avoid as i dont have spare parts.

For a computer that was working perfectly and out of the blue stop working after a simple mantaince has been super disheartening and depressing. Ive spent over 20 hours now trying to fix it doing everything i know how to do, if anyone has any idea of what could be wrong with it, the help would be greatly appricated.

To summerize the issue: the computer will not power on, the led lights on the motherboard are glowing, i can even charge my phone from the Motherboards USB port on the back, the PSU fans does not turn on either when I hit the power button. Only when i jump the PSU will the fan turn on. PSU is almost 100% not the issue as ive tested it extensivly with a multimeter and everything came back normal. CPU fand also doesnt start. Basically nothing happens when I try to start it. No sound or movement what so ever. What could be stopping my computer from powering on when it has worked flawlessly for 6 years?
 

adamgrant520

Commendable
Jan 6, 2019
142
17
1,665
26
that is odd. it would be real hard to break something from a simple thermal paste change. and you seem to know what you are doing so i doubt that is the case :p

to start with that is a high-end motherboard and i imagine should have some kind of debug LED on the surface. This will either be in the form of a 7 segment digit display or 4 separate LED's each corresponding to print on the PCB of the motherboard telling you what is wrong. if its the 7 segment display your manual will tell you what the numbers mean. this should narrow it down as to what is causing the issue
 

InvalidError

Titan
Moderator
-jumped the PSU with a papwr clippp and tested PSU for power problems using a Multimeter at the 24 pin connector plug. All voltage values 3.3/5/12v came back within a +1-3% above of the expect value. This means my PSU is good. condition and outputting the right voltage to everything.

Having breadboarded the build and proving the PSU is good,
The "paperclip" test only proves that the PSU isn't completely dead. The open-circuit (no load) voltages may look fine on a multi-meter but the at-load voltage may not necessarily be up to snuff. You need an oscilloscope to verify that noise and transient response are within limits.

If this is the first time in a long time that your PSU has been completely off for an extended period, maybe its auxiliary supply rail that powers the main converter has gone bad and cannot reliably regulate its output when under load anymore.

While it is unlikely that a relatively high quality PSU like the 1000P2 would fail so soon, material and manufacturing defects do happen.
 
Jun 27, 2021
6
1
15
0
that is odd. it would be real hard to break something from a simple thermal paste change. and you seem to know what you are doing so i doubt that is the case :p

to start with that is a high-end motherboard and i imagine should have some kind of debug LED on the surface. This will either be in the form of a 7 segment digit display or 4 separate LED's each corresponding to print on the PCB of the motherboard telling you what is wrong. if its the 7 segment display your manual will tell you what the numbers mean. this should narrow it down as to what is causing the issue
Unfortunately the Q-code only appear after you power on.
 
Jun 27, 2021
6
1
15
0
The "paperclip" test only proves that the PSU isn't completely dead. The open-circuit (no load) voltages may look fine on a multi-meter but the at-load voltage may not necessarily be up to snuff. You need an oscilloscope to verify that noise and transient response are within limits.

If this is the first time in a long time that your PSU has been completely off for an extended period, maybe its auxiliary supply rail that powers the main converter has gone bad and cannot reliably regulate its output when under load anymore.

While it is unlikely that a relatively high quality PSU like the 1000P2 would fail so soon, material and manufacturing defects do happen.
If that was the case, would the PSU show any kind of life, like fan spinning for a brief second or some sound. Ive put my ear up to it while trying to power it on and i dont hear so much as a buzz. I did turn off the PSU completely the night before so this is possible.
 

InvalidError

Titan
Moderator
If that was the case, would the PSU show any kind of life, like fan spinning for a brief second or some sound.
Yes, depending on the circuit's design, what failed and how. The most typical failure is filter capacitors on the primary-side controller's 15-18V rail going bad. When those fail, the PSU may be able to power up under no-load condition but fail under load because the filter capacitors do not hold enough charge for the controller to drive the FETs. In this case though, most controllers would hit their under-voltage lock-out and stop for a few seconds before retrying.
 
Jun 27, 2021
6
1
15
0
Im honestly at my wits end. Been trying to fix this for over 2 days straight, i got a horrible headache from using my brain too much. Some one please save me before i go out and buy a new cpu and motherboard.
 

adamgrant520

Commendable
Jan 6, 2019
142
17
1,665
26
Unfortunately the Q-code only appear after you power on.
sorry, yes, i mis-read the message. My gut tells me that it would be a motherboard issue. generally speaking if something isnt powering on at all its either the psu, an incorrect connection of cables or the motherboard. since you have tested the psu, I imagine have checked all cable connections, my money lies with the motherboard. how or why it died from a thermal paste replacement im not sure, maybe static or a cap discharging.

obviously i cant say 100% thats what the issue is without having replacement parts to swap in. but thats certainly what it sounds like.
 

ASK THE COMMUNITY

TRENDING THREADS