My 8400, 2yr – 3mo old, suddenly didn’t power on at all. No external lights front or back, no sound (no beep), no fan, nothing changed when I hit power on. Inside the case the small green aux power light on motherboard was on; all looked OK. I first followed procedures on Dell site and then called support. After doing a bit more than the site tests, tech support concluded that it was the motherboard and suggested I buy another from them. This is expensive (out of warranty) and I wasn’t fully convinced that was the answer. (I’ve since seen that 3rd parties offer the ‘mobo’ more cheaply). So I brought the 8400 to a local Geek Squad. They looked at it for several minutes and then pulled and reseated the cpu. They’d seen that loose before on a 775 board. This worked, all rebooted and came up OK. When I got home the 8400 was in the nothing, all dead, status again. I brought it back and this time they also pulled and reseated the CPI boards. Again all OK. I was extremely careful driving home and all was good at home. A few days later (after cleaning lady (a factor or not??)) it was (is) absolutely dead again. I suppose I should just go back to the Geek Squad, but thought I’d try to see if I could learn more on-line. I wondered if anyone else has more experience/knowledge about this OK/totally dead/OK dead pattern. Thanks much for ideas.
