PC shutting down randomly *sigh*

[hulkster]

ive got a home theater PC running windows media center and its been working fine for a while, but now all of a sudden it just starts shutting down at random times.  obvious candidates for replacement are the PSU, RAM, and cpu/fan. 

ive already replaced the RAM with some known working RAM so thats not the problem. 

at this point im curious as to what to replace first.  i notice that if i leave my HTPC on overnight, when i wake up in the morning, its off.  and im talking about a nice shutdown or anything....it just BAM, shuts down.  so its shutting down even when idle at night.  its shut down on me while watching as well....specifically when im trying to watch something from the Hulu Desktop application.  i havent checked the event viewer yet to see if its shutting down at the same time every night or not, but it wouldnt be shutting down right in middle of watching something on Hulu if it was some kind of power saving setting in the BIOS or Windows itself. 

SO....suggestions?  i could just go buy another PSU and start that but man that sucks.  i just dont want to be buying tons of stuff and replacing before it actually works.  help?!

[smalltownguy]

ive got a home theater PC running windows media center and its been working fine for a while, but now all of a sudden it just starts shutting down at random times.  obvious candidates for replacement are the PSU, RAM, and cpu/fan. 

ive already replaced the RAM with some known working RAM so thats not the problem. 

at this point im curious as to what to replace first.  i notice that if i leave my HTPC on overnight, when i wake up in the morning, its off.  and im talking about a nice shutdown or anything....it just BAM, shuts down.  so its shutting down even when idle at night.  its shut down on me while watching as well....specifically when im trying to watch something from the Hulu Desktop application.  i havent checked the event viewer yet to see if its shutting down at the same time every night or not, but it wouldnt be shutting down right in middle of watching something on Hulu if it was some kind of power saving setting in the BIOS or Windows itself. 

SO....suggestions?  i could just go buy another PSU and start that but man that sucks.  i just dont want to be buying tons of stuff and replacing before it actually works.  help?!

That's classic overheating behavior. Have you made upgrades to the PC lately that involved cracking open the case (memory, vid card, other cards, etc)? You may have jostled the CPU, breaking the thermal compound away from the heat sink, causing a degradation of heat transfer. You'll need to re-seat the CPU with fresh thermal compound -- use Arctic Silver. Is the PC in an enclosed space? It could be overheating from lack of airflow. Most folks wouldn't notice that during the winter months, b/c it's cooler. Your night time shutdowns could be due to the fact that you have a digital thermostat that's shutting down the A/C at night, and the rise in temperature is creating enough ambient air temperature to trigger the shutdown.

You might also have mobo problems. Inspect for blown caps. They look like this:



Random shutdowns are almost always due to heat.

[daywane]

I agree with "the thermal compound "
also watch the fans. I would start with new thermal compound .
It is cheep at Radio Shack.
I think it was close to $5.00 for a tube that should last a life time.
after new thermal compound is on and CPU in place watch your CPU fan.
If it slows down on you it is the problem.

If you have a spare power supply laying around I would try that next.
That is what my problem was.

[hulkster]

thanks for the tips guys.  i installed a program called "speedfan" to see if i could find the temps of my cpu and what not.  look at the temps and let me know what you think.  theres that first one that has the flame next to it  and im guessing thats either the psu fan or the cpu fan.  it doesnt really say though.  suggestions?  thoughts?

[hulkster]

in case anyone is reading, that "Temp1" reading has gone up to 61C since i posted the screenshot originally. 

[Dr Zero]

in case anyone is reading, that "Temp1" reading has gone up to 61C since i posted the screenshot originally. 

Here this might help with what temp is ok

http://www.technibble.com/what-is-my-computers-maximum-cpu-temperature/

[Edgedamage]

Check the power connector on the motherboard I had a system that kept shutting off out of the blue. When I went to try a different PSU I noticed the 12+V pins on the connector were brownish black.

[daywane]

I only see 1 reading of a fan.
That must be the CPU fan


Try new thermal grease. first
since you are there also check the legs on your CPU fan.
make sure there not broke.
I do not know what CPU you have but socket 478 seems to break often

[richms]

That's not that hot.

IME its usually PSU instability - either the power supply or the regulators on the board has shot caps as already mentioned.

Hang another PSU on it and see how it goes for a while.

[Dartful Dodger]

ive got a home theater PC running windows media center and its been working fine for a while, but now all of a sudden it just starts shutting down at random times. 

SO....suggestions?

Stop watching that Erin Andrews' video and update your virus protection program.

[hulkster]

not sure if anyone cares or not but i got a new heat sink and my idle temps went from 57C to 37C!     so apparently the stock heat sink was crap.  i know everyone says they are, but this is probably the 10th machine ive ever built and this is the first time ive had a problem with a stock heat sink (i dont overclock or anything).  oh well.

thanks for the tips and advice anyway. 

[smalltownguy]

Glad you figured it out! Thanks for posting your solution. It will help others in the future.

-STG

[SNAAKE]

lol I had the exact same problem. installed a new heatsink/fan with some thermal assist and things are perfect again!

[Dr Zero]

A good heat sink work wonders on temps! Its a trip the factory ones go from ok to way over board.

Has anyone seen the mobo in the oil tank to keep it cool and they were able to fry with the oil 
http://www.hardforum.com/showthread.php?t=1104341

or this beauty

http://www.engadget.com/2007/05/12/puget-custom-computers-mineral-oil-cooled-pc/