System has problems with powering up.

Sometime I can press the on/off button and everthing is ok, other times I have to turn the Power supply off on the back, leave it 5 mins then turn it back on. 5% of the time it boots ok, 10% of the time I have to keep switching the power supply on and off, and the other 85% it will boot after the power supply has been switched off to 5 mins. It is worse when I shut windows down properly.

Another problem that I think is connected is that when I shut the machine down my SCSI CDRW drive makes a clicking noise.

System Spec

ABit KT7A-Raid Mobo
AMD 1.2Ghz CPU
512Mbyte Ram
20Gbyte Boot disk
40Gbyte Slave disk
DVD/CD
CDRW - IDE
CDRW - SCSI
2 Network Cards
32Mbyte TNT2 AGP Graphics
SCSI Card
Sound Blaster 1024 Sound Card

Things I have tried
Replacing CMOS Battery
Tried another power supply - only 235W & Case has 300W
Tried disconnecting all drives other than floppy.
Tried disconnecting SCSI


Any help would be appreciated.

Thanks
ITWhiz

Well, I think a 300W PSU is pushing it a little and a 235W is definitely way under powered.....you have six drives (you didn't list a floppy but I assume you have one) and several fans all using the 12V leg of your PSU, at startup they could use practically all the available power and not leave anything for anything else (even if each drive uses only 25W at startup that is still 150W or half of the available wattage and you are going to need to add the fans in too at about 8W each) and I am not so sure of that many power supplies that will dedicate over half to just the 12V side. (Enermax does, but it is one of the stronger ones, so should some of the other high quality supplies), but most of them won't. So if possible try rudcuing the load and then trying again, but don't reduce it by just on device but several and/or try a tronger power supply.

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mjc
Links list:Computer Links (http://www.dreamwater.org/tech/mjc/index.htm)

Celts are the men that heaven made mad, For all their battles are merry and their songs are all sad.

Removed all devices except for the floppy and Primary Harddrive. Still happened.

Tried a 230W power supply and everything is now okay. Going to invest in a 350W psu.


Many Thanks for you help