I've been messing with my desktop for a while now trying to figure out why it keeps shutting off. I have an HP Media Center PC, 820 Pentium D, 2.8 Ghz. I have replaced the mobo (cuz I was told it was bad), have a new power supply (cuz the fan stopped working on the old one), and cleaned and re-applied thermal paste on the CPU. However, my CPU is still running over 200 degrees F, when max temp for my CPU is 145 degrees F. Does anyone have any suggestions why it's running so hot?

Thanks - Ryan

Make sure there is not too much TIM on the IHS. Make sure the HS is evenly pulled down. Make certain the HSF is spinning. Check in bios that the temp you are seeing in the software is the same as bios.
What software are you using to check temp?
If it's not Real Temp, download it from http://www.techpowerup.com/realtemp/

Not sure what TIM or IHS is. But HS is on evenly, pretty sure, and HSF is spinning. When I power on, I have 2 options: F1 for setup or F2 to continue boot process. In setup --> advanced --> hardware monitor is where I'm seeing the temp. My CPU only stays on for a couple minutes max, so I don't have much time to do anything. On the initial screen that comes up where F1 and F2 are my only options, it also says "floppy disk(s) fail"....if that means anything.

Can you remember what make the original PSU was? Was it Bestec by any chance? If so, I would suspect CPU and possibly ram damage.

Not sure what TIM or IHS is.

Thermal Interface Material. Integrated Heat Spreader.
If you boot into the bios, does the pc shutdown still after a couple of minutes?
Again, what temp is the bios showing compared to the software in Windows?
What is the temperature shutdown in bios set to?

Rik -- the original PSU was HIPRO.

Crunchie -- I spread out the TIM getting rid of some excess. The temp in BIOS CMOS Setup Utility is going over 200 degrees F. I can't keep windows running long enough to check the software temp. I don't see anywhere that says what the shutdown temp is.

It sounds like there is insufficient contact between the IHS and the HS. Only thing I can suggest (if that is the case) is to remove the heat sink and clean off all the TIM on both sides with some isopropyl Alcohol, then put a small (grain of rice size) dollop in the centre of the IHS and then install the HS and try again.
What TIM are you using?

My IHS is attached to my HS, if that matters. I cleaned everything off again and put a small dollop of TIM on. It still overheats. I'm using Dynex Silver Thermal Compound.

Does the heatsink get hot to the touch?

As a temporary lash up to have the system running for long enough to investigate stuff, you could have an external fan bearing down on the CPU. It's a method I've used once before.

Does the heatsink get hot to the touch?

Yep, you need to determine if it is definitely overheating, or if it is a bios problem.
Can you get hold of a heat probe?

The heatsink doesn't get hot to the touch. I put a floor fan on the highest speed on my open box and it ran for just under 6 minutes; however, it shut off when it reached 101C/213F. I reached under the heatsink and it felt pretty warm, but the sides and top were fine. I've got a fan inside my heatsink and also a fan that blows directly on it. Could a bad/damaged CPU be causing this issue?

Not sure what a heat probe is or where to get one.

A heat probe is like a volt meter but it displays temperature. Just Google it. The idea is to verify your temperature. If all the fans etc are working properly, then it might not be temperature.

Thing is, and I'm sure this has occurred to you, if the PC holds up for a few minutes, then there is little wrong with the CPU itself.

So Crunchie's thinking is certainly sound.

So if it's not a temperature problem, then it's a BIOS problem? How do I determine this? I'll see if I can get my hands on a heat probe.

Other thoughts:

Is the CPU new or transferred from the old mobo? I'm thinking about the plastic (transparent) protector they put over the CPU and which has to be removed otherwise it will overheat.

Also you've verified that the fan above the CPU is blowing in the right direction?

I transferred the cpu from the the old mobo. The cpu fan is blowing into the box @ over 3,000rpm.

I'm surprised to learn that there is no heat sink on your CPU and no fan blowing air away from the CPU. I thought the Pentium 820D required this rig?

Anyone else confirm this?

I do have a heatsink on the CPU that has a fan inside it. There's also another fan attached to the case blowing towards the heatsink. Did I put it back in wrong? Is it supposed to blow out of the case and not into it?

I do have a heatsink on the CPU that has a fan inside it. There's also another fan attached to the case blowing towards the heatsink. Did I put it back in wrong? Is it supposed to blow out of the case and not into it?

Ok - a misunderstanding then.

If your computer case has only one fan, it should blow OUT. So should the CPU fan (the one over the CPU).

Are we getting close? Although I'm worried about why it isn't working when the case is on, unless you're blowing the CPU air back in directly over the CPU (the big fan has nothing to do with this - it's supposed to take the hot air away but won't if it's blwon back onto the CPU).

ADDED:

I have seen an article that says you should blow cool air onto the CPU. This works if you have a special case that has more than one case fan and the cool air flow is so directed - AND the incoming air is cool (like less than 28 deg. C). If you only have one fan (apart from the PSU), then you have to conduct heat away.
If you do have an advanced case, then one of the fans has to be blowing air out and be large enough to clear the hot air from the CPU. Fan speeds need to be balanced in a way that maintains a proper air flow. This is usually BIOS controlled through motherboard logic, sensors and instructions to the PSU.

If you have a fan on the front or on the side of the case, then it/they should blow in. If the fan is on the rear or the top of the case, then they should blow out.
You have to make certain that the amount of air going in does not exceed the amount of air going out.
My theory is that if you have more air blowing out, then you create a very slight negative pressure inside the case, allowing for cooler air to be drawn in.
Something else you can try is cleaning off the surfaces of the Heatsink and the IHS on the cpu, put some TIM on and then assemble again.
Before doing anything else, remove the heatsink again and check the contact area. If it is even, the TIM should look the same over the entire surface.
How old is the bios version in the motherboard?

My fan is on the rear of the case and it is blowing out. My heatsink has a fan inside of it and it is blowing out towards the rear fan. The rear fan and the heatsink/fan are about an inch apart. I will have to get some more TIM, as I have ran out. As far as the BIOS version, it says BIOS Revision 3.19 12/8/06 and Core Version 6.0.

Looks like a very old bios version, so perhaps it is not reading the sensor correctly.
If you determine (with use of a temp probe) that the cpu is not overheating, you may have to flash the bios to the latest version.
I mentioned earlier about an safety feature in the bios that will turn off the pc if the cpu gets too hot. You will need to locate it in the bios and see what it is set to.
There may be an advanced options menu that you can access if you cannot find it in the basic menu.
Not sure how you would access it on yours. All I know is that F9 brings mine up once I am in the bios.

I've been messing with my desktop for a while now trying to figure out why it keeps shutting off. I have an HP Media Center PC, 820 Pentium D, 2.8 Ghz. I have replaced the mobo (cuz I was told it was bad), have a new power supply (cuz the fan stopped working on the old one), and cleaned and re-applied thermal paste on the CPU. However, my CPU is still running over 200 degrees F, when max temp for my CPU is 145 degrees F. Does anyone have any suggestions why it's running so hot?

Thanks - Ryan

200 degress, wow. Ur problem worse than mine. mine overheats but have found no cause nor cure.

Rik -- the original PSU was HIPRO.

Crunchie -- I spread out the TIM getting rid of some excess. The temp in BIOS CMOS Setup Utility is going over 200 degrees F. I can't keep windows running long enough to check the software temp. I don't see anywhere that says what the shutdown temp is.

Bios / pc health / shut down (system heat, cpu heat, shut down, shut down)
Your bios may be different

Apparently I needed a new heatsink (even though the one I had still appeared to be working because the fan was still turning). System works great now! Thank you everyone for your assistance!!!!

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