How to tell if CPU is bricked?

[need2sleep]

A friend's computer needed cleaning and she wasn't running it because it overheated frequently. I cleaned it. The CPU heatsink, among other things, was severely clogged. After cleaning and replacing CPU grease, reassembling the heatsink, putting it all back together, I turn it on.

I have high speed fan right away. Looks like it goes through device checking - I see momentary lights on the DVD drives, for example. Nothing shows on the monitor at all. Is this an indication of a bricked CPU? Is there a decisive way to check for a bricked CPU?

Thanks.

 

[hizodge]

Well there should be either a light indicator on the board or a series of beeps. How to read these should be found somewhere in the motherboard manual.

Just out of curiosity, how did you clean it?

 

[smorizio]

Could be simple issue of the CPU got pulled from the CPU slot when you took off the heat sink. Unlock the heat sink but don't take it off then unlock the CPU and lightly press down on the CPU then lock it back in. If it not a walked CPU check to see if any thermal paste leaked onto the CPU pins.

 

[need2sleep]

Well there should be either a light indicator on the board or a series of beeps. How to read these should be found somewhere in the motherboard manual.

Just out of curiosity, how did you clean it?

I used arctic clean 1 & 2. I left the CPU in place. I tried to be careful not to spill over. Then I applied that diamond paste (forget name), about 5 mm pea size in the middle of the CPU. I had trouble reattaching the heatsink - the retainer clasps were difficult to get attached quickly as I envisioned the paste spreading in relationship to the uneven pressure due to this problem.

After I turned it on with the aforementioned reactions, it went off by itself. Then it wouldn't turn on even after waiting 1/2 hour. There is a light on the power supply that illuminates when power cord is plugged in. The cord was in, but the light was not on. I switched cords with known good cord. No effect. Could a bricked CPU cause a power supply to fail?

Cascading failures - don't you love them?

Thanks.

 

[need2sleep]

Could be simple issue of the CPU got pulled from the CPU slot when you took off the heat sink. Unlock the heat sink but don't take it off then unlock the CPU and lightly press down on the CPU then lock it back in. If it not a walked CPU check to see if any thermal paste leaked onto the CPU pins.

OK, I'll keep that in mind. I don't want to unlock the heatsink, without cleaning and reapplying the thermal paste, right? So this will be last resort, but at least your post gives me a last resort. Thanks.

 

[TenPc]

CPU's are really quite difficult to "brick" unless the thermal paste has dried up, there was none to begin with or too much applied then the cpu fries in its own juices.

Did you blow out the dust inside the heasink, clean the muck off the fans fins? Did the PSU have dust clogged in it?
The problem might actually be an old PSU that is no longer able to perform its duty and needs to be sent to the PSU retirement home.

Does the PSU actually turn on at all, even for an instant?

 

[need2sleep]

CPU's are really quite difficult to "brick" unless the thermal paste has dried up, there was none to begin with or too much applied then the cpu fries in its own juices.

The thermal paste was old, but could still be partially wiped off, so I take it was still viable. It was well within the boundaries of the CPU. There appeared to be a barrier outlining the boundaries of the CPU imprinted on the bottom of the heat sink. The old CPU paste had some thin spots in it, but pretty much over most of the area of the CPU, I would guess 85-90%.

Did you blow out the dust inside the heat sink, clean the muck off the fans fins? Did the PSU have dust clogged in it?
The problem might actually be an old PSU that is no longer able to perform its duty and needs to be sent to the PSU retirement home.

I blew off the dust on the heat sink. I cleaned off the muck on the heat sink fan (really bad clogging there) and then the case fan as well. I air dusted the rest of the cabinet. I could not adequately force air into the PSU from inside the case, but I did what I could. I did notice a thick shroud of dust clinging to some cables inside the PSU when I was done. The case had a heat sink inside of it, and wondered how I would clean that off without opening its case, which someone once told me never to do. I did not see any dust on the heat sink in the PSU, however.

Does the PSU actually turn on at all, even for an instant?

The PSU has a light in the back of it near the plug. It used to stay on when the plug was in whether the machine was on or off. I assume as long at the plug had power, the light was enabled. Now when I plug in a power cord, the light enables only for a second or two, then goes out.

After that one start up, I noticed the power switch in the front panel was "stuck" in the on position after the machine had stopped running of its own accord. I could only correct it by taking off the front cover and replacing it. Though the switch works again (goes in, stays in, until you hit it, then comes out again to an off position), nothing happens when the switch is placed into the on position and the cord is in the PSU.

 

[TenPc]

"The thermal paste was old" how could you tell? If thermal paste is dry in any way then it is no loger doing its job. The cpu should be covered 100% usually, although some AMD cpu's don't require a full coverage. I'd need to go check.

The front panel on button, if it sticks, you need to make sure that it doesn't stick or is replaced, it might just have sweat gunk in the button hole.
When you hold the power button in for more than 4 seconds, on purpose, you are really just telling the bios to shut down the PC.

What brand / model is the PSU?

 

[need2sleep]

The PSU is a HIPRO, 250W. Model HP-D2537F3R.

I have new information!

I believe I took off the system board power prior to pulling the heat sink, because the power cord stretched over it and I could foresee upcoming contention, then forgot to reconnect prior to testing machine.

Now I need some education. If the board didn't have power, how is it when I tested the fans, they ran? The fans are connected to pins on the board. This was a very short test on the bench. Then when I turned it all on for real, it ran for a short time? This explains why I had no monitor output and no network light when I plugged in the network cable, something I forgot to mention earlier. But I don't understand. Did I blow the PSU by not connecting the board power? How could the BIOS have polled devices like DVD and CD drives - or maybe it didn't - they were just powering up of their own accord since they were independent of board power; they just "did their thing."

I still don't get a solid light when plugging in the power cord on the back of the PSU, and the machine still won't come on. I have yet to check your suggestion, TenPC - gunk in the bottom of the front panel switch, which is my next task.

Thanks and apologies, if needed.

 

[TenPc]

250 Watt????
It must be an old system with Windows XP.

The 12v 4 pin connector does give power to the Graphics card and some other devices so you would still get power to other hardware.
It is reasonably safe to leave it off but not for any length of time, though.

Thermal Paste procedure -
http://www.tomshardware.co.uk/cooling-air-pressure-heatsink,review-32320-9.html

I think we will need the other hardware specs to make sure that the PSU is not under powered, especially if the cpu is more than Pentium 4 based.
The video card would only need to bne 128mb vram or at most 256mb but anything higher would cause issues with power requirement.
250 watt is really only about 180 watts on the 12v rail.

Edit -
The PSU is a HP preferred PSU and is only adequate with the original hardware at the time of purchase, any other additions would require additional watts and only the same manufacturer model.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817174031

It is only a 20 pin connector but its ATX which don't usually have enough amps on the 3.3 and 5v rails but considering it is HP, and not a split 20+4 pin connector, it would be, should be, what is required.

Edit 3 -
The LED on the back of the power supply should NOT blink!
http://justpowersupplies.com/hipro-hp-d2537f3r-power-supply.htm

 

[need2sleep]

250 Watt????
It must be an old system with Windows XP.

Yes, it's from 2003, I think.

especially if the cpu is more than Pentium 4 based

It is a Pentium 4, 3.0 Ghz.

I will digest "Thermal Paste Procedure" - thanks.

The video card would only need to be 128mb vram or at most 256mb but anything higher would cause issues with power requirement.

Using an HP P/N 5187-3703, V9520/128M ASUS video card.

The PSU is a HP preferred PSU and is only adequate with the original hardware at the time of purchase, any other additions would require additional watts and only the same manufacturer model.

I will check with the owner.

 

[hizodge]

Did you clean anything apart from the CPU heatspreader? If there are no POST error messages such as beeps or the like, it's just likely that you bumped into some wires. So check that everything is connected properly.

 

[TenPc]

Thermal paste is corrosive it's to be applied between the metals of the CPU and the heatsink, if it gets on the PCB board it will eat it for breakfast lunch and dinner. Some CPU's have a heat monitor next to them, they are some small gold strips, not sure about your motherboard, I thought I just mention it before checking but if the thermal paste gets on them, it corrupts the temps in the bios and may also cause cpu failure in extreme cases.