red light flashing - no power

[yamataz1]

I have a Compaq EVO D31, the fan in the power source quit working, so I replaced the power source (yes it is the correct one). Now when I attempt to turn on the computer all 3 fans will run for about 2-4 seconds then stop and then the red light on the front of the unit flashes. This does this without any drives hooked up at all. If I put the old power supply back in it works just fine (but again no fan, which is why I replaced it). Does anyone have a solution?

[davy]

Yikes thats odd, wonder why the fans won't work with the replacement power supply... it is a new one I guess, even so new power supplies can be faulty... the fans run from the 12V rail.

Obviously the unit's not even booting as it hasn't had time to do so, you'll get boot and be able to access bios set up screen with just the CPU, RAM and graphic card installed the rest can be disconnected as they don't come into play.

First of all check the fans, ensure they are not sticky and free to move.. with the power off, they should offer no resistance when turned.

So from this we are looking at the mobo any bad capacitors about, their tops should be nice n' flat? The power supply we've tried.. sometimes re-inserting the graphic card can work wonders same could be said for the RAM cards but it's usually the video card what suffers this kind of trouble, so we'll leave the RAM cards to you.

A duff bios battery can cause all sorts of problems, sometimes a reboot can work wonders, if it's over about three years old then it's worthy of replacement as it will be way past it's best.

DO NOTE removing this for more than two minutes will cause the bios to default to the factory setting, so you may need to go through the settings... there's usually a default setting you can use.

Dare I mention the CPU, this itself just might want a re-fix, I'd be tempted to leave this a very last resort in case of damage.

Does the power plug on the original power supply to the mobo look OK? Sometimes the connections comes loose and passing about 20 Amps will cause the connectors to heat up, there will be discoloration around the nylon plug and pins if this was the case.

Davy