|"I believe that I damaged the IDE controller on the motherboard. "|
That's extremely unlikely if it was working before you changed the cpu.
I have NEVER come across one that actually was, unless the mboard was damaged.
What were you attempting to do?
Were you having problems you thought replacing the cpu should fix, or were you trying to upgrade the cpu?
If you were trying to upgrade the cpu, the cpu has to be compatible with what the mboard supports and be one the mboard bios can detect - if it isn't your mboard may not boot normally.
If you replaced the cpu because the mboard was not booting, that probably is NOT why the mboard was not booting.
If you still have the cpu that was in it before, try installing that.
The Dell Dimension 4600 has a reputation of having a power supply that is more likely to fail, and it often damages the mboard while failing. That may apply to your model too. Did the power supply fail and you replaced it? The effects of any damage done sometimes don't show up right away.
Failing power supplies are common and can cause your symptoms.
Check your PS.
See response 4 in this:
If the PS seems to be fine (the only way to tell for sure is to try it with another working computer) .......
Open up your case and examine the mboard to see if you have bad capacitors, and/or other findable signs of mboard damage .
This was the original bad capacitor problem - has some example pictures.
History of why the exploding capacitors and which mboard makers were affected:
What to look for, mboard symptoms, example pictures:
Home page that site
- what the problem is caused by
- he says there are STILL bad capacitors on more recent mboards.
Pictures of blown capacitors, other components, power supplies, Athlon cpu's, etc.: