new build...no post...HELP!

[$chlitz]

ok, so i bought my pops a new mobo/cpu/ram for xmas to upgrade his ancient machine. he's no hardcore user--just internet and email, so i went with a budget setup. abit KD7R board, duron 1800, 256mb pc2100 DDR, coolermaster heatsink/fan. i assembled the machine as usual, but when i fired it up the fans and drives spin up for about a second, then it shuts down. i swapped in a new 350w power supply, same results. i stripped the machine down to board/cpu/ram/video--same results. i've reset the cmos jumper and even pulled the battery--same results. the led on the board is lit as long as the power supply is connected, front panel leds work (well, only for the 1-2 seconds that the machine stays running), but i get no beeps or anything else. i've assembled my share of machines in the past, but i've never had this problem before. i'm stumped. if anyone can give me some ideas as to where i should start troubleshooting, that would be great. i'd really like to get this machine up and running asap. thanks a bunch!

[spyder003]

It sounds like the heatsink may not be seated properly... Have you double checked it? Did you use all of the standoffs for the motherboard? It sounds like it could also be a loose standoff or screw behind the motherboard.

[$chlitz]

Originally Posted by spyder003 It sounds like the heatsink may not be seated properly... Have you double checked it? Did you use all of the standoffs for the motherboard? It sounds like it could also be a loose standoff or screw behind the motherboard.

i can only hope it is that simple...in fact, the old case has seen better days, and a standoff or two WAS loose--they were just stripping the threads right out of the case as i screwed them tight. i may have also skipped one or two since the darn mobo had no hardware with it and i only had so many standoffs in my supply arsenal. i never figured that would make all the difference in the world. learn something new every day. i'll go buy a new case and see if that solves the problem. (fingers crossed...) thanks!

[Panama Red]

To eliminate the case as possible culprit, follow the directions in this thread.

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

All components must be assembled outside the case.

[Electric Gnome]

This has happened to me, once on a new build, and once on a repair. In both cases the heatsink was not properly fitted. I removed said item cleaned both surfaces that contact each other, popped on some thermal compound and presto!
Do not forget that too much thermal compound is as bad as too little, it causes the heat to be retained if you put too much on, odd I know but true.
My moneys on the heatsink.

[$chlitz]

well, i removed the heatsink, cleaned everything, applied some new thermal compound and carefully reassembled the system in a brand new case, making sure to use all the standoffs with nylon washers under the screws. BINGO! it posted right up on the first try. my bet is it was grounding out in the crappy old case, since some of the standoffs were loose (the threads in the case wall were stripped). thanks for the help, everyone. dad will sure be happy to get the new machine--it should be quite a step up from his ancient K6-2/450!