I'm stumped: Computer won't turn on, heat issue

Hello everyone. Recently, my mom (sweet as she is) told me that her computer wont turn on. She usually leaves her computer running, but let me know (after it broke) that it has been mentioning on its case temp monitor that the computer has been getting hot and the light would turn red. She said she 'tried' to turn it off when she saw the warning but never told me about it until now.

I poked around inside and found that the computer wont turn on at all, but there is a green light on the motherboard if the computer is plugged in. Also, the fan on the heat sink for the CPU wasn't spinning because the fan seems to have tilted in its craddle and now wont budge (Perhaps it melted into that position?). My guess is the CPU is fried, but after I plugged the computer in, I put my head close to the motherboard and heard a faint noise coming from the PSU, and I'm not sure if that is normal (don't forget the green light on the motherboard was lit).

Let me check on the specs and I'll give it a post in a minute... thanks in advance for your welcome suggestions

I threw the CPU fan away in anticipation of getting a new one.

It is a P5NT-Deluxe (775 Socket) and the PSU is a LSP Ultra 750W ATX Power Supply. These parts are all less than 3 years old, and it has an Nvidia Evga Geforce GTX 280 GPU. I had set the computer a while ago on power saving mode because my mother doesn't game

Any guesses as to what I should do? I don't have much I can swap for to test if something went bad or not. Do you think the board could have fried if the CPU fried on top of it? Do you think I need a new PSU?

DustSailor said:

but there is a green light on the motherboard if the computer is plugged in.

That's just indicating the motherboard is receiving power. Tis normal.

I put my head close to the motherboard and heard a faint noise coming from the PSU, and I'm not sure if that is normal

It depends on the noise. Is it like a high-pitched whine perchance? Coil/capacitor whine is fairly common.


At this stage, it's feasible that CPU could have fried if it's been running at max temps for an extended period of time (as suggested by a non-working HSF fan)

If you get a replacement HSF and it's still dead - then it's possibly time to consider a replacement CPU.

A faulty PSU is a possibility, but when faced with a dead fan + overheating - the CPU is the most likely point of failure and the first place to start.

You don't think the motherboard would have fried under the CPU?

Also, the green light indicates to me that the motherboard is indeed receiving power (as you mentioned), so the noise coming from the PSU is most likely, as you say, "Coil/capacitor whine," at my best guess.

I can't be 100% sure though that the PSU isn't acting faulty in some way, yet somehow giving enough power to light that MB light. This is highly unlikely, I'll wager, and I can't imagine chance would dictate that her PSU breaks down at the same time as her CPU.

So far it looks like I will be going ahead and ordering a new CPU and heat-sink for her.

There is a slim possibility that the mobo is damaged, although a fried socket is unlikely.

When presented with a 'suddenly dead' PC, it could be any number of things. But like a detective, you start with the most likely suspect. In this case, the long term, high CPU temp. Then you eliminate suspects one by one. Fingers crossed that the most likely is the culprit.

Try to start it with a new heatsink fan, it won't start without one.

Then you can go from there.

Dave76 said:

Try to start it with a new heatsink fan, it won't start without one.

Then you can go from there.

I didn't know that, so the first line of buisness is to get a heatsink. Wonder if, after the heatsink broke down, the computer just wouldn't turn on because of it, giving it a chance that the cpu got hot but didn't fry? Could this be possible? I could probably test this by hooking a fan or such (maybe a heatsink if a fan won't do the trick) from another computer into my mothers, right? I'll see bout this once I go to her house next

It's a safety feature, if you don't have a fan connected to the CPU Fan header the system won't start.

You can put a fan on the CPU heatsink, plug it into the CPU Fan header and see if it will start.

Let us know how it's going.

Think I'll start here: Cooler Master - Hyper TX3 92mm CPU Cooling Fan with Heat Sink - RR-910-HTX3-GP
Best buy is almost the closest we have out here to a computer store, but if they don't have it, I'll have to order online. This computer shouldn't normally get too hot. Then I'll look into getting another CPU if hooking up the heatsink won't allow me to turn the computer's power on. She doesn't need anything spectacular, just something that will open Word or such document and a browser lol

Dave76 said:

Try to start it with a new heatsink fan, it won't start without one.

Actually it depends. I haven't done it a long time, but you can boot a PC without a heatsink attached.

I did it to a Pentium D - The CPU emit a high, tortured electronic squeal, heat up very rapidly and was very soon followed by a swift shutdown.