I recently had a athlon 1600+, 512 mb ram, 40gb hd, 64mb radeon video running without any problems. From a trade I go a athlon 2400 cpu. I replaced the 1600 with the 2400 and rebooted. I got no video signal, HD and Floppy lights up, keyboard flashes once, but nothing else happens. I thought it must be a bad cpu from the trade so I put back in the old 1600 athlon. Same thing. Then I assumed the motherboard must have took a dive, so I purchased a new motherboard. Once again, same results. So I now have to decide where to go next, either power supply gone bad or BOTH cpu's dead. I find the latter to be unlikely. I did test the power supply with a voltimeter by probing the p4-p5 wire sets. yellow+black gives off 12.32 and red+black gives 4.96 volts. This is with the power supply seated into the motherboard with no other components hooked up except cpu. So I am asking advice on whether I should go for the new power supply or CPU.
You see i still have the athlon 1600 cpu. It was working fine before I tried the 2400, so I am thinking odds are both cpu's wouldn't have went bad, but neither one works in either motherboard.
you could also have either a dead motherboard or 1 with a screwed up bios caused by the 2400 chip. so now have a motherboard that might be scrap & 1 if not 2 cpu's that are garbage. can risk the 1600 on another board to see if posts or not as your option. if posts than the bios is messed up & might be able to be reflashed but depends if soldered to motherboard or in a socket
I have 2 motherboards:ECS and a brand new PCchips, both are rated for either cpu as far as bus speeds, memory, chipsets. The ECS motherboard was the one working fine with the ahtlon 1600 cpu, until I tried the 2400 cpu. The PCchips board is brand new and neither cpu works in it as well. But boards do the same thing with either cpu, no video signal, floppy and hard drive engage, keyboard flashes, then nothing. This is why I am perplexed, with the power supply "seemingly" working I get no POST, no video, which would lead a person to think cpu dead, however, this would mean that BOTH cpu's were damaged as I pretty much have ruled out motherboards as the cause. But, then for 2 cpu's to go bad is not likely.
but if the bad cpu screwed up both bioses than you won't get a post at all which means no video or nothing as the bios tells the cpu what to do till the os kicks in
I took a voltmeter and jumped the ground-on pins on the atx connector. All the voltages are on or above the requirements except the +12 and -12 pins, they both test at 10.86 I'm curious if that is to low. I know I need another power supply as this one is a 250 watt and it was running 2 dvd-r drives, 2 HD, 512mb ram, 64mb video, and athlon 1600+ cpu, but now since I'm stuck without another power supply to test with, whether I need another cpu, mb, power supply, or all 3. If anyone knows if the below 12 volt reading will stop boot, I'd appreciate it. Also did power supply test while hooked to motherboard, same voltages. Btw I did test the p4-p5 connections above and got proper voltages, but not from the 20-pin AT
