PC will not boot, interesting scenario.

[Carswell90]

So recently I moved into a new house. During the move, the heatsink in my PC came loose.

This is my setup: Motherboard- Intel DP35DP, CPU- Intel Q6600 Quad Core @ 2.4 gHz, Video Card- AMD 4870HD, 500 GB HD, 2 Gigs of RAM, a 500 W PSU, and I was running Windows XP Pro.

As I was busy and I didn't have any time initally to look at the PC, my brother volunteered to have a look. (He is not very intelligent when it comes to technology, as I would find out)

Initially, my brother took the heatsink out and tried to boot it without it. He said it would turn on for a couple seconds, beep, then shut off. This was done twice I believe. After, he attempted to re-attach the heatsink, but had issues getting all 4 pins into the mobo. He used a cable tie to fasten it down. This somehow worked and the PC ran fine to my amazement, however I quickly bought some thermal paste and applied it, as this was not done before (like I said, he isn't intelligent). After taking the mobo out, properly applying the thermal paste and re-attaching the heatsink, the PC ran fine to my surprise.

This worked until about a day and a half later, while I was using the PC, I heard a pop sound and the PC shut off. I smelled a burning smell. After looking inside the PC, and not seeing any signs of burnt components, I attempted to turn the PC on. As I press the power button, the light on my PSU flashes once and goes off, meanwhile the PSU fan turns on, as do the case fans. The CPU fans do NOT turn on, neither does anything else in the case. However, the motherboard light is on. I'm not the most tech-savvy person but I believe it has to be the processor being messed up, however it is also strange that the PSU acts the way it does.

Any help would be appreciated so I can locate the problem and replace the parts needed, with my brother's money of course.

 

[turkey3_scratch]

Are you sure
1) your heat sink is fully installed properly? If it is not working the motherboard might detect that it is not or the heat and automatically shut off.
2) Check for loose wires. A guy recently had a similar problem and it was a loose wire (but no burning smell)

 

[aldan]

the popping sound was likely a capacitor ending its life.likely the psu.look on the motherboard first tho for domed or leaking capacitors (those little things that look like cans).if you dont see any its probably your psu.do you have another psu to try or any way to test the psu?

 

[Carswell90]

I do have a spare PSU to use, so I'm going to try that. Are the symptoms those of a messed CPU? Because I for one was astounded it was still working after he tried to boot it without the heatsink/new thermal paste.

 

[aldan]

doesnt sound like the cpu.they will shutdown before they burn up,which was what was happening when your brother tried to boot it without the heatsink.if i was a betting man i would bet on the psu as the culprit.

 

[Carswell90]

doesnt sound like the cpu.they will shutdown before they burn up,which was what was happening when your brother tried to boot it without the heatsink.if i was a betting man i would bet on the psu as the culprit.

Thanks, I'll give the spare PSU a try and update this afterwards.

 

[Carswell90]

Bought a new power supply, installed it, didn't fix the problem. When I press the power button, the psu fan twitches once, almost like it's gonna turn on but it doesn't. The CPU fan also does this, it just twitches once. The two case fans turn on. The green light on the mobo turns on. Also now I can hear a sort of buzzing sound as soon as I turn the psu power button on (buzzing starts and ends when the green light on the motherboard goes on and off respectively).

 

[aldan]

look carefully at the motherboard for burned components,especially capacitors.do you have onboard graphics or a dedicated graphics card?if you have a card try powering the pc up without the graphics card.

 

[Carswell90]

look carefully at the motherboard for burned components,especially capacitors.do you have onboard graphics or a dedicated graphics card?if you have a card try powering the pc up without the graphics card.

I have an ATI AMD4870HD, I will try starting up without the card. I will keep updating this, thanks again for the replies.

 

[Carswell90]

Ok so I decide to try breadboarding to help isolate my issue. I took the mobo, psu, and heatsink and plugged it all in. After shorting the power pins, the mobo came on, and the psu and heatsink fans worked fine. I got the 3 long beeps, added a stick of memory, tried again and this time no beeps. Does this mean the issue is not with any of the components I've used this far (psu, cpu/heatsink, ram)? Should I move on and start testing the video card etc.?

 

[Carswell90]

Well fellas, I figured it out. After breadboarding, and realizing the problem did NOT lie with the GPU, CPU, PSU, RAM, HDD, or motherboard, I realized that it had to be an issue with the case. I noticed on the HDA wires, one had bubbled up, like it had popped. Sure enough after unplugging this the PC turned on. Very strange, and not what I expected.