Dell Optiplex 520.

What's up? I have this dell computer my friend gave me to fix and for some reason the computer starts up and I try to re-install XP and I get into the set-up screen. It starts to install window and then after a while the green light in the front changes to an orange light and the computer turns off. I tried to switch hard drives and the same thing happens with another drive. I'm thinking it's the motherboard would anyone know?

thanks,

:confusedrolleyes

 

have you tried another power supply?

 

Yes, it could be the power supply. It could also be the CPU overheating (check the heatsink and fan; be sure it's mounted correctly with fresh thermal goop and be sure the fan and heatsink are clean and dust-free and be sure the fan is spinning free and easy), it could also be faulty capacitors on the motherboard. If any of them are even slightly popped ('popped' means the tops are bowed outward and not perfectly flat) or if they have some off-white (or beige or brown or black) crud on top then the capacitors have failed which means the motherboard requires replacing. Some Dells have BIOS settings that can be set to power down or go into a 'power save' mode after a given time of activity. Since you probably aren't using the keyboard or mouse, the BIOS may recognize the install as 'inactivity' and shut down the PC. So check the BIOS and disable any power-saving features. You can set that stuff in Windows if it's needed.