System won't always boot

[Rachet]

I bought a Soyo 6ba+IV motherboard a couple of years back and started to build a system with it when I got a deal on an Asus CUSL2 board so I repacked my Soyo board and stored it in the closet.

Well I decided I would build a PC for my folks from the parts I have laying around, so I put a system together using the Soyo motherboard.

The system will not always boot up, i don't get a post, no beeps, nothing on my screen. The PS fan works, the cpu fan works, that is all that appears to work. If I shut the system off and restart it, 90% of the time the system will boot up fine and the system runs okay.

I am using the slower IDE slots as I was having problems with the Ulta slots so I disabled them in the Device Manager.
I reflashed my Bios to the most current version. I changed my PS from a 250PS to a 300PS. The system has 448 MB of ram, an Nvidia Vanta AGP video card, 2 maxtor hard drives, Toshiba 32x Cd player, an Nic card and a 16 Bit Soundblaster card. The system is running XP Pro.
Any one have an idea on why the system doesn't always boot?

I am assuming it is Bios related since I don't receive any beeps when it doesn't boot

[codered6651]

Have you tried pulling everything out of the computer except for the cpu/heatsink and the psu. Make sure the power switch and speakers are hooked up so you can listen for any beeps. Once you have done this and you still don't get any beeps you may have a problem with either the mobo, cpu, or psu. You never mentioned what CPU you are using. Is this your mobo?

[glc]

Offspec PSU, improperly mounted motherboard, faulty or miscabled/misjumpered drive, faulty expansion card. Weak bios battery.


http://forum.pcmech.com/showthread.php?t=12753

[Rick Hall]

I have seen this caused by something attached to a USB port. Try disconnecting everything from the USB ports and try like that. If this works then start reconnecting to the USB ports until you find the culprit.

[Rachet]

The system is using a Pentium II 400 processor.

There is nothing connected to the USB ports.

I tried 2 different PS, the first was a 250Watt (Proman) and the current is a 300 Watt(Codgen), even though these are not high quality PS, they have worked in systems before without problems.

The battery on the motherboard is old, I will get a new one ASAP.

I will recheck my cables, jumpers, and mounting of my motherboard and see if that helps.

Remember it will boot up correctly about 90% of the time.

Thanks for all your suggestions, I will try them all to see if any one of them holds the cure.

[Cricket]

Try the out of case troubleshooter (the link in glc's post) and see if the computer will boot up everytime when it's out of the case. If it does, check to see that any stand off installed in the motherboard mounting tray is matched up to the mounting holes in the motherboard. Remove any stray ones.

Cricket