Desktop not working after dusting

Mike Funnelly

Hows it going, was there this morning and i decided to give the pc a dusting to clean it out, so i got at it with the vacuum and sucked the dust out of it, i also removed the heatsink on the cpu, when i plugged it back in and turned the power on, the fans run, as does the LED on the motherboard but the power light on the front of the computer goes yellow.

Any suggestions, on how to get it runnning again?

Deliverance XXV

Did you reapply thermal compound on heatsink when re-seating it back on the CPU?

Mike Funnelly

no i didn't, when i took it out i just popped it out with the cpu and dusted it then put it straight back in. It's in a dell desktop

duridian

You shouldn't go near the inside of your computer with a vacuum cleaner. With the powerful suction like that, the air rushing by the (usually) plastic attachments of the vacuum cleaner can generate static electricity, something which can damage pc parts if it jumps to them. Brush type attachments are the worst of all because they have nylon bristles. The proper way to dust the innards is to use a can of compressed air.
Now you might have got lucky and just dislodged something like the memory or graphics card, so you should check that everything is securely in place, but if you damaged something with static then you could be in trouble unless you have some spare parts to swap in and out so as to narrow down which component is at fault. You could also check the diagnostic LEDs on the rear of the Dell, and compare them with your manual to see what they say is the problem.
It also worries me a bit that you said the CPU "popped" out with the heatsink...

mathias

no i didn't, when i took it out i just popped it out with the cpu and dusted it then put it straight back in.

When you Dusted it , did you Dust the pins on the CPU , I take it you mean that the whole assembly came out , fan heatsink and CPU all stuck together ?

Mike Funnelly

yeah, it all came out together,dusted the fins of the heatsink never touched the pins, put it back in again and the power indicator light on the case is showing yellow instead of green, although the fans are running on the powersource and the extractor to cool the cpu

duridian

Mike Funnelly wrote: »

yeah, it all came out together

That's bad man. The heatsink should be removed first, then the cpu.
I'm going to assume it is one of the older black 'n grey Dells, most of which were based on Socket 478 processors.
In the most of the black 'n grey Dells, to remove the heat sink from the cpu you should first remove the 4 screws, then slightly rotate the heatsink, just a few degrees left and right.
Do not rotate it too much, a tiny bit is all that is needed.This breaks the adhesion which the thermal paste causes between the heatsink and cpu causes. If you don't do this then the heatsink can rip the cpu out of its socket when you pull it. The danger here is that a pin (or several pins) can get broken off the cpu, because the cpu is at this point held by the retainer of the processor socket which grips the pins.
Look at this wikipedia page to see a Socket 478 processor socket:
http://en.wikipedia.org/wiki/Socket_478
The lever on the right of the socket pictured on wikipedia is used to lock the cpu into place. When the lever is raised the socket is "open" and you can remove or insert a processor. When it is laid down flat the socket is "closed" and you cannot insert or remove a processor because the locking mechanism is in place around the pinholes. Attempting to insert a cpu into a locked socket would almost certainly cause damage, bend pins etc.

mathias

OK , here is what I can gather ,

If the power light is solid steady yellow (not blinking), that usually indicates a malfunctioning or incorrectly detected device.

Usually, the memory is not installed correctly, a card isn't installed right, or the processor is failing.

Now , considering what happened , there are two possibilities , either the CPU is not inserted correctly , or its dead.

It could quite easily be dead , what you did is not recommended. Unless you were wearing a grounding strap , dusting the heatsink as you did will have built up quite a charge on the whole assembly , ( ESD , and electrostatic charge) and this would have discharged on contact with the socket. Possibly killing the processor as a result.

The whole assemble will have been conductive due to the metal heatsink , conductive paste , processor die , and processor pins being a path for discharge.

To check , you are going to have to disassemble the processor again. This time , ground yourself before touching the parts , either touch a metal part of the case or get an ESD strap.

Take the processor off the heatsink altogether , clean of the heatsink paste , re-apply some heatsink paste ( arctic silver is one of the best ) and put it all back together. Then try it again.

With a bit of luck it will work , hopefully you just disturbed the heatsink paste on removing it the first time and it is just refusing to boot because of a high initial temperature.

If the worst has happened , and the processor is blown , then theres no bringing it back and you are going to need a new one.

Edit : Duridian has a good point there too , if you didnt release the cpu lever and the processor still came out then that is really bad ...check for damaged pins.