So i just recently upgraded my computer's motherboard, cpu and ram a week ago. From the get go there was problems. Firstly, sometimes my monitor wouldn't recognize that the computer was plugged into it, and was sending out data, so it just said no inputs. This would happen multiple times, but i found out that just turning off the psu and turning it back on, then powering up would fix it. I had to do this each morning.
I came down today to my computer and i found it to have the same problem, so i switched off the psu, turned it back on and tried booting up. No response. I tried this again and when i turned on the psu, the case fans started running (without me pressing the powerswitch) and a small place on the motherboard started glowing red and giving off smoke after a couple seconds. i switched the psu off after i saw this happen.
After that i just thought it was the motherboard was shorting out or something, so i replaced the motherboard with my older one which has a different cpu and ram on it, and it still starts when i turn on the psu (not touching the power button) and my monitor does not recognize it, this one does not blow up however.
well just to give you guys some reference here's my setup (with the part upgraded to in brackets)
psu: hiper type r psu 580 w
mobo: asus a8n-e (asus p5k-e)
processor: amd athlon 3700+ san diego (intel core 2 duo 6750)
ram: ocz platinum forget timings (crucial ballistix ddr2 1066 forget timings)
hd: samsung spinpoint 200gb
gfx card: evga 7800gt co
monitor: samsung 940b