starting the computer when the front switch does not work

Question

Hi All, I have an Optiplex 780 after a powerout yesterday, I cannot start the computer. I have disconnected the mains power for at least twenty minutes, but still no response. There is a single yellow, (orange?), LED glowing on the main board near the end of the SIMM. Anybody know what I should be looking for and where it may be found? All responses appreciated. Regards Chris

redxps630 · Answer

Orange LED is normal and it should be on when power is connected. It gets power from 5V standby in psu.

First Try reset CMOs jumper on motherboard after unplugging power cord and draining power from system by pressing power button.

If CMOS reset does not bring any change, do you have a 780 MT or SFF? If MT, try borrow a verified working ATX psu with 24/4 pin connectors to test.

crb99 · Answer

Hi redxps630, thanks for your response.

I'll set about that reset, and come back to you with the result.

Sadly, (though not really), I live in a very isolated spot in Scotland, so psus are hard to come by.

best regards

Chris

redxps630 · Answer

If the power button blinks amber, and some of the led diagnostic lights are on, those are not good signs. no worries of psu as the issue may be the motherboard. no guarantee it can be revived. your best hope now is to reset CMOs. my 780 SFF has a steady led on motherboard ON as soon as power plugged in, but a blinking amber power button that does Not turn on anything not even the front fan. And I verified my psu works. Hope you are more lucky than me.

Mary G · Answer

One thing to try before you give up-- remove all the removable cards even video and try to boot. Listen for a startup. If that works, add the video card and try again. Add any other card and reboot again until you find the bad one. You should also replace all cables with new ones. Power, network, etc. can be blown by a power surge. OK it's more than one thing...

crb99 · Answer

Thanks folks, I guess it is the psu. I'll deal with that and go no further with this enquiry. Thanks to all. Happy Christmas

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