CPU overheated PC wont turn on again

I was testing a setting on my i5 750 with prime95, it shot up to 99C in 2-3 minutes and the whole PC shut off instantly. I unplugged the power cord and replugged it. when i press the power button, phase led 1 flashes once and nothing else happens.(flash only happens once after resetting power to PSU, if i press the power button again without resetting power to the PSU, absolutly nothing happens). however the USB ports have constant power to them whenever the PSU is plugged in.

motherboard is a gigabyte ga-p55m-ud2

 

Unless your computer has the ability to shut down if critical temperatures are reached AND that was enabled at an appropriate level, it's possible something fried and caused the shut down. Did you notice any warning messages on the monitor before it shut down?

Does it make any sounds when it boots up? One or more beeps? Long beeps? Short beeps? The sequence of beeps can help with troubleshooting. Notice anything on the monitor? Tried another monitor? If you have onboard video and a video card, try the other one.

EDIT:
"boots up" probably wasn't well put - I should have said do you hear any beeps when you turn on the computer.

 

One of the first rules of overclocking,if you try a setting that doesn't work reset the cmos.

If you haven't reset a bios before,disconnect from the ac,press the power button to drain the last of the power from the system, find the small coin shaped battery and remove for 20secs,replace,reconnect AC and try to power up.

Welcome to the forum

 

Computer doesn't turn on at all. If I unplug the psu and replug it back, 1 of 4 phase LEDs on the motherboard flash on the FIRST push of the power button. If I press the power button again, absolutely nothing until I reset power again.

No warning on the screen or anything when it turned off it just instantly shut off

Am I going to have to replace the motherboard, processor, or both?

 

Hi,

PSU has safety circuit that resets when you remove power. Over current, over voltage and under voltage set it off. I think it's telling you that something is shorted and drawing excessive current. Disconnect things until it stops doing that and you will know which device is doing it. If it never stops the MB is probably the culprit.

Good Luck,

Jim

 

I may be misunderstanding but the USB ports. Have constant enery when there is power to the psu. The LEDs in my mouse and joystick stay lit. So I don't think the psu is tripping off. Or is it??

 

Hi again,

If the +5 is on, USB, mouse etc, then you are correct, the PSU is not tripping out. Sounded like you meant you had to reset it to try again. Have you tried resetting the BIOS? May be worth a try.

More Luck,

Jim

 

Done it twice, no difference

 

It's tough to find which component is stopping a computer from booting but for testing remove all uneeded add in cards,cdrom,harddrive's ect. Use one stick of memory in dimm 0 and try to boot,then swap to a different stick and try to boot.

To test the power supply remove from the computer,with a paper clip short the green and any black wire on the motherboard connector and the psu should fire into life,test all the voltages on the PSU.

Basically to test is it is the cpu which it most likely is you need another 1366 cpu or another 1366 motherboard that fits the CPU.

 

Am I correct in thinking since the failure came from overheating my CPU, that most likely replacing it will fix it? Will a burned out CPU keep a pc from turning on??

I will try the techniques provided. How do I tell if it's mb or CPU. I'm certain it's one or the other

 

Yes it won't turn on at all without a working CPU.

You put a 1366 cpu into your motherboard and test it or put your cpu into a 1366 motherboard.

If you don't have another laying around which most people don't you have to take it to a store and ask them to test it for you,they usually have all current motherboards and cpu's to test them.

The other option is to RMA your CPU without testing it,all boxed Intel CPU's are warranted for 3 years,you will then know your CPU is working when its returned.

 

So my mb is a LGA1156 that's apparently obsolete already. Newegg only offers 1 quad core thats out of my price range since I'm kinda poor. Anyone know where I can find a good fast one for cheap. New or used doesn't matter

 

My apologies I misread your CPU info,1156.

 

Ordered a i5 760 on amazon for $140. It's going to take up to a week to receive. I really hope it fixes it. I will report back when I have tried it. Thanks to all who's helped me with this difficult situation

 

Installed replacement processor. Still doing exact same thing. I don't know what to do

 

very sorry for 3 posts, i dont know how to edit a post on this forum.

I unplugged HDD, dvd rom, removed gpu card: all 4 led's flash once quickly instead of just the first.

tested PSU, all pins read either 3, 5, or 12 volts so i think its fine

If i plug the big white connector into the MB and unplug the ATX_12V_2X4 connector it turns on for 1 sec then cuts out for 5, then repeats the same on 1 off 5.

any thoughts???

 

I would conclude your motherboard is damaged,sorry

Its hard to come to any other conclusion.

There's a 10min edit limit,the edit button is at the bottom right of the message window next to quote.

 

Ok I will try to find some money somewhere and get another motherboard. I will post again when I have the result.

 

Have you sent the CPU back? I would and exchange it for a motherboard,Amazon will exchange it no problem whatsoever you should only have to pay return postage,if they ask for a reason just say its incompatible.

http://www.amazon.com/gp/help/customer/display.html?ie=UTF8&nodeId=15015711

You should be able to get a 1156 mobo for less than $140.

Good luck Niceguy,I can see this has been quite an ordeal for you I hope it turns out this time

 

Just curious, how hard is it to switch to another brand of motherboard or should I replace it with the same one?? I saw an intel board I really like, but my Gigabyte board is available for cheap on eBay.

 

Its exactly the same there is no difference,make sure it supports your cpu,make sure it supports your memory,if you have an ide hard drive or cdrom make sure it has IDE.

Everything else is down to your personal specification and what features you'd prefer,do you want onboard video,do you want a X16 pci-E slot,do you want SLI as an option,do you want usb 3,do you want overclocking features,do you need lots of pci-e slots for lots of add in cards.

Loosely if you bough pretty much any 1156 motherboard without checking anything it will work no problem with your current hardware 90% of the time,the other 10% can be eliminated by checking the cpu support list at the manufacturers website and of course the maximum memory speed if you've bought fast memory.

 

How are you going with this?

Couple of thoughts have occurred to me and I welcome other people's comments - I haven't had to deal with many systems where something has fried.

The phase led on the motherboard flashes; that says power to the motherboard but I'm guessing doesn't tell you if it's damaged. Comments, people?

The other thing that has occurred to me is to do with when you turn it on. I'm not entirely sure what you mean by resetting power to the motherboard. Do you mean disconnecting the power cable and then plugging it in again and powering on? Can you turn the computer off by holding down the power button? According to your motherboard manual, (Power Management Setup - try section 2.7 on page 54.) instant off when holding the power button is the default but it can be set to only turn off after the button is pressed for 4 seconds. (A great feature for when little people who've learnt the power of the button are around! They usually don't have the knowledge and patience to keep holding it for 4 seconds. :-D) So theory goes that pressing and/or holding down your power button should kill the power - does it? - if so, what happens if you then try turning on again?

When you do get up and running again, make sure you have the specs for what temperature your CPU can tolerate (available at the manufacturer's site) before you start tweaking again. I'm not sure how to get those details but someone here would be able to help you and what research I did suggests that most CPUs don't cope above the high 60's or early 70's.

EDIT: Oops! Forgot to leave the link to the motherboard manual for those who want it:
http://www.gigabyte.us/products/product-page.aspx?pid=3287#manual

 

Yes resetting power means pulling the power cord out or simply turning the power switch off and on. As far as the power button I had already known that but means nothing for this issue since it doesn't power up at all but I greatly appreciate the effort. Still shopping for a motherboard. I been trying to get a great deal on eBay something around $50. Came close a couple times (one person ended the auction early)

 

not sure who is still keeping an eye on this, but i just got my motherboard back from RMA. no details on what they repaired but PC turns on now. thanks to all who have helped. I concidered this now a closed case. Now i just need to try and sell my extra i5 750 processor.