I have no power to the unit. I took off the cover and nothing is moving. Fan twitches but does not spin. No lights or response from anything else.

no one I know can repair power supplies only fix is replace it

It may be the fan itself some models wont power up unless they detect cesistance through the fan to prevent the unit from over heating.

bad power supply. just replace

> bad power supply

Try an ordinary lamp in the wall-socket -- to make sure that a circuit-breaker inside your home has not "tripped", i.e., no power to anything that plugs in.

If there is an on/off switch beside where the power-cord connects to the power-supply, switch it to the "off" ("zero") position.

Unplug the AC cord from the power-supply.

While watching the fan inside the power-supply, and/or watching the fan on top of the CPU, plug-in the AC cord. One of the fans may "twitch", if there is power.

Flip that rocker-switch to the "on" ("one") position, and see if one of the fans "twitches".
Also, look on the motherboard for a small lamp -- it may go on if the AC power-cord is connected,
or may go on when that "back" switch is set to "on".

Try a different power-supply. If still nothing, then it's your motherboard that got "fried".

Sounds like a bearing went bad. Unplug the unit and grab the fan blades and move them. If they slop around inside the motor, you have bad bearings.

I don't remember which fan is the number two fan but usually there is a fan on the lamp and on the DMD. So to find out just take the lamp door cover off and you should hold down the switch so the TV will run and see if the DMD fan is turning on or not. If it is turning on then check the lamp fan by sliding out the light engine. For either lamp check to make sure there isn't anything preventing the fan from moving. Like wires being pushed into the fan or something like that. If there is nothing there then while you are turning on the TV try to spin the fan to see if maybe you hit a dead spot on the fan motor. If that works then power on and off the unit to see if it starts working fine again. If it doesn't keep working then replace the fan. If the fan doesn't start spinning at all then follow the wires for it to make sure they didn't get pulled out of probably the DMD board if it is a Samsung. Then make sure they are seated properly, if no change then check voltage and make sure it is getting voltage. If there is voltage then replace the fan. If no voltage then replace the DMD (if it is a Samsung).

sounds like your motherboard has hard it try dissconnecting the everything exept CPU power supply keyboard and screen and see if you can get it to come up with the bios, if it still dosnt work unplug the fan on the CPU and turn it on then see if that works (dont leave for more than 1min without the heatsink fan spinning as it can cause the processor to overheat anything less than a min you ok. just long enough to see if theres any signs of life on the screen. hope this helps

It sounds like you have a bad fan capacitor.
You might try replacing it, they don't cost very much.

Not just 'lightning strike' but any 'dead' PC.

Unpower the unit and then take off the access side panel. While looking into the unit, put the power back on (plug it in, but DO NOT press the Power button yet). - LED's should light, but no fans should turn. Still looking at the fans - especially the CPU fan, press the Power button and if they twitch then your unit power supply has died.

If they spin for a few seconds then die, look at the capacitors by the memory - if they bulge and are 'wet' then the motherbioard has died - ask Dell for replacement! (This is common, but Dell will only recognise it at the point of walking into the court, then only if you sign a secrecy agreement/gagging order!).

The air intake vents in the rear were clogged with dust. They needed to be brushed and vaccumed.