will not start, at all

[shnikey]

I just upgraded my mb and processor to a soyo 5EMA+ and a k6-2 450mhz. I put it in hooked it all up pressed the power button and nothing...nothing. This happend once before(with another mb)when I was tinkering around, when that happened I took it out put in another case, it worked. Then I put it back in my good case and it worked again. I do not get it. I have checked to make sure everything is connected. Whats wrong this is a big problem. Please help.
Shnikey

[stu]

hmmm dunno power supply would be the obvious one, mbo isnt sitting properly in the case, hmm dunno guess you're gunna have to try it in another case again see what happens

[Underclocked]

Try clearing CMOS (clear real-time clock) and triple check all connections, especially those from the case switches and L.E.D.s.
Reseat your video and memory cards, remove the other cards, and give it a whirl. Good luck.

[Vampiel]

Sounds like you put the main power connectors to the MB the wrong way, that would explain you putting it in the old case and it working, then back in the same one and it worked, prob just got the power cord to the MB in the wrong slots. If you here it rev up but no video then you may have a HD jumper wrong, this only normally ahppens with older HD's though. Also make sure you have all the cables that hook up from the case to the MB correctly (ide jumper, power, turbo, LED, etc...) you know the bundle of jumpers that a whole bunch of different colors coming out of the case.