Constant Booting Problem

[Camando]

Hey i'm trying to get a old pc up and running. The problem is that when you turn the damn thing on. It boots for about 5 seconds. then turns off. Then reboots and then just cycles through the same thing until you kill the power to the PSU. It's running a ASUS PK5 SE MOBO. I have a GTS 8800 series graph card sitting in there. And i'm pretty sure the CPU is Intel core 2 duo (socket 775 anyway). I have basically done an isolation test by removing all the components one by one and turning the PC on with each removal of a component. I've managed to strip it down to just the PSU, PCU, and Heat sync + CPU fan, and i'm still getting the same problem. FYI the PSU is 550 watt and its not a cheapy. and the total watt usage for the pc is 320+. Any ideas? Or should i just throw it out the window?

 

[Guest]

Don't throw it out of the window you have a better then average system mainboard. You might have to strip the thing down to just the mainboard remove the bois battery before you remove the mainboard from the case.
What I would do is to take the mainboard out let me say. Then I would inspect the mainboard for loose connections of the mainboard heatsink to the board. If the mainboard heatsink is firmly on there then I would(because the mainboard is out of the case). Get a small screwdriver and remove the mainboard heatsink anyway. Put new thermal compound on the heatsink area's that go to the northbridge, southbridge. and check to see if the thermal blanket over the voltage regulators is not worn away. Also while heatsink is off the mainboard(mainboard heatsink I speak of) check for smoothness attempt to straighten by hand if not. With the new thermal compound on the heatsink attach back on mainboard, but before you do buy some thermal blanketing cut a small square the size of the southbridge computer chip then cut a little square hole in the square piece of thermal blanketing that you cut. the little square hole in the middle should be the size of the little square heatplate on top of the chip. This is done to ensure that the transistors and whatnot on top of the chip are unaffected by the metal from the heatsink. Do the same procedure for the northbridge.
Once I would have put the mainboard heatsink back on the mainboard being carful not to overtighten(just enough to snug it down. Then I would turn my attention to the case. Most older cases did not line up perfect with mainboards even if they are atx form factor ready. I would check the standoff screws(what the mainboard sits on. Make sure they line up with the holes on the mainboard. If any standoff does not line up perfect remove the standoff. In the end you only need four stand off screws. Then put the screw in the mainboard which drive into the stand offs. If any standoff is stripped then discard the stand off.
Put the bois battery back in then all the other stuff.
The reason I gave you all that info is because you said it try to boot meaning that something is shown on the monitor screen which tells me it is very much alive. But due to southbridge overheating on alot of older mainboard lga775 mainboards you could bring it back to life(that only if you visually see something on your computer monitor that shows computer booting process. If you do take any of this info into consideration remember(ALWAYS REMOVE THE BOIS BATTERY BEFORE YOU WORK ON YOUR MAINBOARD).

 

[Guest]

If all your getting is the actual boot process via l.e.d light that are attached to the mainboard or just a on process with no monitor activated then more then likely that mainboard will need to be sent to a place that reconditions them. I personally would not buy into the thoery of going to ebay and buying a new bois for that mainboard because that is more then likly not going to work but thats just me and my past experiences trying that! 🙁