i have a 2 yo acer m3100 amd 64x2 it started shutting down randomly no restart no error screen after several storms i talked to computer shop guy he said it sounded like psu so i bought a new 400 watt to replace 250 watt worked great for 2 days then it got worse wont stay on 5 seconds so i disconnected every thing and opened case unplugged hdd then tried starting 5 seconds later same thing had board tested at shop and cpu the board was bad so i bought a new asus m3a78 board and a new case and built my first' frankenstein' computer i reused ram 3gb and 500 hdd which has vista premium installed and dvd burner after it all went back together it worked great for a few hours then shut down on wife same mo wife said shut down again today i checked temp with everest it said cpu 2 was 69 c i freaked then restarted to check bios temp temp was 39c to 45 c im a poor man and the 154.00 for board and case nearly broke me and build tested my skills since i have never done anything but add ram many years ago any body with some suggestions would be greatly appreciated

Hi jefro and welcome. Understand that checking the temps is the BIOS tells you little, unless it is high there too. This is because running the BIOS Setup Menu is about the least demanding task you can ask of the computer. So it is good it is low in the BIOS, but not conclusive you don't have a heat problem.

Did you use TIM?

thanks for info and no i did not use new 'grease' but i will try also how do i accurately monitor current temp and log any abnormal temp when shut down occurs bye the way it shut down about 30 min ago while i was not on thanks again should i reformat and reinstall vista or maybe use a better surge suppressor?

You need TIM.

Your motherboard utilities disk should have a monitoring program (or check for a more recent version on your motherboard or PC maker's website). If none, I recommend CoreTemp for newer Intel and AMD64 CPUs. SpeedFan is a great and popular alternative, or you can try Motherboard Monitor. Unfortunately, I have found that these programs often have problems properly identifying and labeling the sensor they are reading. The temperatures shown are as accurate as the inexpensive, low-tech sensors will allow, but it may say System Fan instead of CPU Fan. Fortunately, the programs do allow you to edit the labels, so I use Everest to verify the temperatures (as it is able to put sensor to label correctly), then edit the label in the monitoring program. In Everest, look under Computer > Sensor, then wait a couple seconds for the readings to appear. Unfortunately, Everest does not minimize to the system tray to show real-time temperatures, otherwise, you could use Everest instead of the others.

69 C is quite high. I would get an can of compressed air and out the CPU heatsink and the fans making sure that they all work. Your computer needs to be off when cleaning out the heat sink. Then I would install Prime95 and run it for about 30 min to an hour unless it starts to get over 65 C. You said that you didn't replace the RAM so are you sure that it compatible with your new MB?

thanks guys everything has been cleaned inside of case looks new and i chose board primarilly on cpu and ram so i would not have to replace im stumped sinc eboard and psu are new.ram and cpu were checked at shop the only part thas has not been tested is hdd i ran a virus scan with avg and norton and found a virus with avg i beleive it was sheu or something similar i dont have a vista disk to reinstall i appreciate all the input from you guys since i am not a skilled tech just one thas has to figure it out as i go keep the suggestions coming and maybe we can figure this thing out

New electronics generally fails upon first power up, within the first few hours of operation, or after years of dedicated service. Yours is still under warranty if only a couple days old. It could be the board if all else has been checked.