I have a Dell 8400. Shortly after powering on the PC it seems over heat and shut down. When powering up, the fan in the power supply spins very slowly at first and speeds up after a while, all the while making an unusual noise. After it shuts down, the green light on the power button just blinks. The CPU fan seems to be running fine. Is this a simple case of the power supply being bad?


9 Years
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Last Post by caperjack


but you will probably need a new PC

the older dells have custom power supplies, and if you stick in a normal one, it will fry the motherboard


Thanks for your advice. I'm not averse to buying a new PC, but it seems odd that I can't replace the PSU. Worse case, couldn't I buy it direct from Dell and slap it in? That seems cheaper than buying a new PC. Also, and I'm not being smart, how can a "normal" PSU fry the motherboard. Are there differences in the level of electrical currents between PSUs? I figured they are all the same in terms of output.



You MAY be able to find a normal ATX to DELL PSU adapter cable... MAY being the key word.

Is the system dusty? Is the CPU heatsink free of blockage and dust? Use some compressed air and clean out the fans, the PSU, and the CPU heatsink. It is possible the PSU or CPU is just overheating and nothing is wrong at all. Give it a shot... if it works you save yourself some time and money.


you need to \check though

SOME Dells use the custom PSUs, SOME dont - but theres no easy way to tell the difference. if you end up using the converter cable then find out that you do in fact have a normal one, then it will fry your pc also.

Ask on the dell community forums. They are very good indede.


Weird ,Not saying anyone is wrong about the topic here but, i have 3 dells here right at the moment ,all power supplies look the same a regular atx ones and have same power data on the stickers as regular ones ,and the 20 pin connector plugs into my psu tester ,only thing is the -5v, light doesn't light up on the tester .
also ,its been about 2 yrs now but i one time put a regular psu in a dell dimentions 2350 or something like that ,i remember need 4 pin a adapter wire for a hdd or cdrom, or something like that , and never heard from owner yet !but hest a few hundred miles away ,so maybe he just never got back to me when it all burnt up.

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