dell dimension 5100 power up problems?

Question

i have a dell dimension 5100 thats giving me some problem, the problem is that it dont power up, the light is on the motherboard but thats it, the funny thing is that if you leave it with the power cable plugged in it suddenly boots up then loses power within a couple of minutes, but then the power supply fan cuts out but the processor fan keeps running very slowly until it seems until all the power has gone, this never makes the mother board light go out. i have taken out all the pci and graphics cards and but the memory back one by one but nothing changes. like i said it boots up by itself then loses it, between boots it takes a couple of hours, according to the manual and the diagnostics lights on the front its a hardware problem ( solid amber light ). but taking out all the hardware makes no difference because it comes on when it wants. any help much appreciated. many thanks.

the processor fan normallr runs really fast as it does when it first reboots, then slows down when the power supply fan cuts out

Answer 1

sounds like the power supply is giving out, suggest you give Dave a ring and ask if you could borrow that spare one he's got
at least it will eliminate one possibility or you could contact dell they have a 3year warranty on their products and you can transfer the warranty

Answer 2

Sounds like either the power supply is crapping out or the CPU fan is knackered & drawing excess power. I'd suspect the former.

Mind you, a good cleanout & de-fluff might help first.

Answer 3

Open the side and see if the motherboard is getting power when you start. I suspect what you are hearing is the fan on the cpu trying to run and failing. If so, you need a power supply. Make sure you get the correct one if you need a new one.

Answer 4

Change the CPU fan this is an overheating problem.

Does the fan run slowly all the time.