Unkown Boot up problem

I am running a non-brand computer that is having difficulty booting up. Everything, including peripherals, has power to it, but the computer restarts right after the memory test. I am unable to access the BIOS settings, as it restarts before I can access it. I have swapped out both the RAM and hard drive as well as replaced the hard drive cable. Nothing seems to work, and I can't get far enough into a boot to boot from a CD. Any ideas?

 

Have you reset and cleared the BIOS using the jumper on the motherboard? Have you tried a new BIOS battery? Also, remove any and all expansion cards and devices not essential to booting: unplug the floppy drive, the CD drive(s), any PCI cards like modems and sound cards, if you have on board video and a video card, remove the video card and plug the monitor into the on board video, unplug the hard drive too (both the data cable and power cable). If it still restarts right away with everything disconnected, it's either bad RAM (which you said you already tried), a bad processor (unlikely), bad power supply, or bad motherboard (most likely). I have seen bad floppy drives cause instant reboots, and I've seen bad CD drives cause PCs to lock up during POST and prevent the user from entering the BIOS. Computers can do strange things... in a situation like this, it's best to strip the PC down to just the needed essentials to pinpoint the problem.

BTW- did the PC ever work normally? Is this a new problem on PC that was previously OK?

Good luck! Keep us posted, and Welcome to Major Geeks! :wave :major