I can't say 'first-hand' what happened - I was out of town when my wife had the lock up. The computer locked during normal operation and will not restart. No posting to screen...nothing - monitor displays "no connection". I had upgraded to a high-end video card and added 512MB ram about two months ago. When starting, the main power light is on and the HDD indicator lights but nothing else - doesn't sound like it is spinning up. When I got back in town yesterday - the light to one of the CDRWs was on, but its not making it to that now. Stuff tried: (i) brought system back to OEM status, removed extra HDD, removed extra DIMM, removed AGP V-card, removed extra CDRW - nothing (ii) reset CMOS - nothing (iii) checked 5/12V off PSU - 5.01V and 11.4V - not confident or knowledgeable enough to check on board voltages. PSU and CPU fans are running as they should. Should I even try to replace the PSU - I may have over taxed it with the upgrades? or should I chalk it up to a Kentucky Fried motherboard? Is there anything else I can check? Thanx.