# Dell XPS 400 won't power on



## koga88 (Aug 16, 2012)

Hello, I have a Dell XPS 400 desktop which is about six years old at this point. The computer has been running fine with no issues over the last few years, but today it suddenly will not power on.

It was working fine a few hours before, but when a big thunderstorm started coming in, I shut it down just to be safe. However six hours later when I tried to turn the computer back on, it would not power on in the slightest, with no lights coming on in the front panel or even the sound of a fan starting up.

All of the other electronics on the same surge protector work fine and had no issues during the storm, and when I opened up my computer my motherboard had a green light on it. I am unsure of how to fix this or what the problem could even be. Could it be something with the power switch itself or is the computer itself messed up?


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## Tyree (May 10, 2009)

A failed PSU is the first thing that comes to mind. A PSU can supply enough power to light the Mobo LED but not have sufficient power to actually boot the PC.
Does your Dell have a light on the PSU? Does it have diagnostic lights?
Try clearing the CMOS and see if it will come back to life.


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## koga88 (Aug 16, 2012)

I unfortunately don't see any other lights on inside of the computer when it is plugged in nor are there any diagnostic lights. Also I am unsure of what a CMOS is or how to clear it, as I am not quite the most tech intelligent when it comes to computers.


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## Tyree (May 10, 2009)

wkw427 said:


> The CMOS is the small wrist watch battery on the motherboard. Remove it, unplug the computer from the wall, and wait five minutes before you put the battery back in and plug the computer back in to clear it


The above information is not correct and could cause serious damage to your PC.
Shut down the PC, UNPLUG the power cord to the PSU, push the case power button several times and then remove the CMOS battery for a few minutes.


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## wkw427 (Nov 9, 2008)

The CMOS is the small wrist watch battery on the motherboard. unplug the computer from the wall, Remove it, , and wait five minutes before you put the battery back in and plug the computer back in to clear it


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## Wrench97 (May 10, 2008)

Is the power light on the front blinking, yellow, green, on solid or not coming on at all?
First thing on that model to try is unplug the power press and hold the power button several times plug the power cord back in and see if it boots.

Another thing to note on a XPS 400 the battery is a pain to get to you are better off using the Clr_Rtc jumper > Documentation


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