What PSU for AMD XP?

I am trying to upgrade my computer to Athlon 1800 XP, but when I turn it on it doesn’t post, but the fan and harddisk spins. I replaced the motherboard, CPU and RAM to no avail. I’ve wasted a good 3 weeks without a computer!

I am having second thoughts about my PSU which is 300 watt. The thing is I have tried 3 other 300 watt PSU and they don’t help. Also they have AMD sticker of approval - shouldn’t this be enough?

Can anyone post what PSU rating they have with their Athlon XP…

I will try to get a 400 watt PSU sometime soon.


The number of Watts doesn’t matter.

You should have
20A @ 3,3V
30A @ 5V

Cheap crappy 300W PSU’s have 14A @ 3,3V, while e.g. Enermax 300W allows almost 30A @ 3,3V. Therefore, Enermax 300W will probably work if lower quality 300W PSUs fail…

alexnoe is wright.

20A @ 3,3V and
30A @ 5V


300W should be fine (although my old one went down the river recently).
Have you checked all settings in the BIOS?
Does your machine say it has found an Athlon 1800+, XXX MB memory & your drives ok at boot up? If not there’s your problem
Also a good idea to make sure all leads and cards plugged in firmly and correctly.
Sorry if I’m teaching my granny to suck eggs…she does dribble a lot.

If you have tested with AMD approved power supplies and the system doesn’t POST, this is probably not a power supply problem.

A properly working 300 watt rated AMD approved power supply would not cause a failure to POST with a normal set of devices attached.

What kind of video card are you using? Try replacing it with a known good card and see if it will POST. If you have changed the AGP settings in the system BIOS, a setting may be incompatible with your video card which could cause failure to POST. In this case, you may have to use a PCI video card to boot and enter the BIOS, then change the AGP video settings back to default or other safe settings.

Check the switches on the motherboard are correct for your setup if it requires some manual setting

Have your tryed to just plug the video card in and nothing else? I had a keyboard once that locked my computer up from boot up. Try to boot it up bare bones… just video card, monitor. See if something comes up on your monitor. …oh and use only one memory stick in the motherboard also.

Truman: What is your motherboard?

Enermax, Zalman or Antec PSU’s really work fine… a 300W will do for standard situations. For better filled up cases you’d better get a heavier model.

Wow thanks for the replies. I’ll check my PSU amp ratings.

I’ve already tried just trying the video card + monitor and nothing else plugged in, also I tried an old NVidia TNT2 card - also failed. My video card is ATI Radeon All In Wonder.

I can’t even post so no chance of getting into BIOS and I’ve tried resetting the CMOS. Also I checked jumper settings at least 10 times over and tried bus speeds of 100MHz and 133MHz. The motherboard is a new one PC Chips M825, however I got it replaced free of charge to another brand: Gigabyte and still have same problems.

I am getting a bit frustrated now. Unless I am unlucky to have 2 failed AMD Athlon XP CPUs or 2 failed motherboard!!

I should have gone for Pentium!! But I like the cheap+speed of AMD.:frowning:

You did try it with only one memery stick? I had a problem once with mixing double sided memery sticks with single sided. But if you did then you dont have much left but a power supply. :rolleyes: Is the motherboard in the case right? Not shorted to something? Try it with it out of the case if you can.