Where to start troubleshooting

[Peacekeeper100]

I have had this computer 2.5 years. Haven't opened that case in 8 months. I shut it off and two hours later it wouldn't boot. I have an MSI motherboard (K7T266Pro2-RU) with a Athlon XP 1700+. The MB has a D-bracket indicating 4 red lights. Meaning it is haulting on the CPU check. MSI sent me an e-mail saying it could be the CPU, MB not giving enough power, or the power supply. Since all the fans and HD start up I am leaning away from the power supply (an Enermax 365). My question is what is the most likely cause. Being the end of the semester I am a little pressed for time and wanted some opitions on where to start when I get home tonight. I have another computer that has another 1700+ in it, and an Asus MB (A7N266-VM).
I was going to start with a visual check of the MB capictors to make sure they are not leaking. Then I was thinking I was going to swap the CPUs from the two computers, but being the lever is under the edge of one of the heatsinks that is going to be a problem. Any another opions on this. I am guessing the most likely cause is the MB, 2nd the CPU, then the PS.

 

[tkistre]

I would start with the easiest things first. Unplug all unneccesary items like the hard drive, CDRom, Floppy, Extra PCI devices, etc... If available, check memory, since it's easy and quick to do. Then I'd check power supply and processor. I've used MSI boards in the past that have the D-bracket. It's great when it works, but it is not always a truly reliable troubleshooter. Also, the power supply may surprise you. I've had power supplies before come on and power everything, but were still faulty. I have a tester now that actually test all of the voltages, 5v -/+, 12v -/+, etc... and puts a load on the power supply. It has been very handy. Hope find your problem.

 

[Peacekeeper100]

Funny thing. I unplugged all the internal power cords that were not needed and made sure all the others were tight. Still didn't work. So I unplugged all the external connections and moved the computer near the other one planning on using the PS of the other computer. I decided to test it one last time. This time it worked. I hooked everthing back up and no problems. The only thing I can think is that the power cord was not making a good connection and couldn't pull enough current either at the surge protector or at the PS and disconnecting it fixed the problem.


Thanks for you help

 

[Zepper]

Boilerplate-01:
. Common causes of failure to boot (no video, no beeps):
1- RAM, CPU and/or AGP video card not seated properly, or a bent pin.
2- Drive data cable on upside down or only on half the pins or shifted . a pin or two (usually Floppy or Zip drives).
3- CMOS needs to be cleared (AC power must usually be disconnected or any attempt to clear CMOS may fail) Unless your mobo does not use a power-off CMOS clear - check your mobo manual for specific info.
4- On some new mobos there is a CPU protection feature (esp. on Asus/Asrock Athlon/Socket A mobos) that will not allow the system to start if there is no fan (or a fan without a working speed sensor wire) connected to the fan power connector on the mobo (specifically marked "CPU Fan"). If you tried to start your machine without a fan properly connected, you have to attach a proper and working fan and clear the CMOS before it will boot.
.bh.