GATEWAY DX4300 WON'T BOOT; FAN CONTINUES TO RUN; NO SIGNAL TO MONITOR

turn the pc off completely... turn on the monitor and wait for no signal... now time it till the no signal switches to put the monitor into standby.
now turn the power on the pc at the wall. turn the monitor on and as soon as you see no signal turn the pc on.
if the monitor jumps into standby as soon as you hit the pc power button and in less time it took to switch after no signal it means the cpu has an issue. its either dead or disconnected.
if the fans spin up and the monitor takes its normal amount of time to go into standby then check the leads on the hdd.

what do you mean it wont turn off completley? if you just connect the 20-24 pin and not the atx lead you may cause a problem with the rest of the board not booting as it should. also check the power switch on the case. also plugging in the power cord will cause a voltage surge so make sure the psu is switched off or you may be causing it to trip in some way.

Interesting. I've been having similar problems with my DX 4300 for the past couple of months. I used to let it sleep at night, but it got to where I couldn't wake it up, so I started leaving it run. If I "restart", or it's only off briefly, it starts fine. Yesterday I transferred my files to a new computer, planning on restoring Win 7 on this, hoping that would fix it. But researching tonight, I don't think that will help.

I moved this 4300X to a different location with an old spare monitor/mouse/keyboard, and left it off last night. When I hit the power button today, I got the same old problem. I can hear the disc working, and the fan, but there's no blue light, and the signal to my monitor leaves quickly. I shut it off and on about 3 times with the same results. Then I turned it on and walked away because I've found that often when I do that, when I come back in 10 minutes, everything's up and waiting for me. (Not every time, but most times.) Worked today--and I'm still using it.--AND, once in awhile it hangs while shutting down, and I have to hold the power down for almost 10 seconds.

Tomorrow I'm going to try this CMOS reset suggestion (link following). I think I can handle that one. I just got done reading '05 posts about a certain Dell model with a similar problem. By the time I got to the end of the thread, there was a list of 83 people with the same problem, same computer, that had to replace their CPUs.

http://pcsupport.about.com/od/findbysymptom/ht/nothingo...
http://pcsupport.about.com/od/fixtheproblem/tp/clearcmo...

http://www.tomshardware.com/forum/274293-28-gateway-dx4... - Doesn't look good...

Thanks for the faithful contributors who said it was the power supply I have the same computer with the symptoms: will not wake up, will not shut off with holding down the off/on button (must pull the plug), when plug in again the fan runs but does not boot! Installed a new power supply (500 watts rather that original 300 watt) and bingo -- works like a charm! Gateway DX4300-11

Thanks again faithful

Mathguy