I went to use my computer after it had been on all day and the power button was flashing. Checked all connections, cleaned out dust. Still no power. Help please.

If a PC idels it could go into habernation try unpluging it for 5 or 10 min then restore power
Did this do anything ?[

We tried everything. Someone said it could be the power supply. How do we know if it's the motherboard? Don't want to spend too much money. My husband is going to try a new power supply. What do you think? Thanks!

In my experience, the power supply is usually the culprit if the machine is absolutely dead.

What I do before replacing anything is start with a 'bare bones' system. Meaning, you disconnect everything from the machine (monitor, printer, network, speakers, external devices,) and disconnect everything that you have added to the board (PCI/AGP cards, added RAM, new internal hard drive, USB controllers, anything that didn't come with the machine). You should end up just your tower and your power cord.

If it does work with everything removed, start re-connecting everything 1 component at a time. If it stops working when you re-connect a certain item, then chances are it's that item.

But if it doesn't come on after removing everything, then most likely it's a power supply problem or your mobo is shot. Every once in a while you'll get a bad power cord, but this is pretty rare.

Anyway, between those 2 components, the power supply is generally the first to go. Especially if you have a lot of dust (or a bug problem) in the area where you computer was.

Now, trying to figure out which of these 2 is bad is kind of difficult unless you have an extra of either lying around. Personally, I've never actually seen a bad motherboard cause the entire machine to die unless it's a custom build. Usually the machine will hang (can't POST), repeatedly restart at boot, give light or sound codes, or illuminate your keyboard LEDs to where they can't be toggled.

As for the power supply, if you noticed any kind of surge (you can sense it) or popping when connecting or disconnecting the power cord - it's bad or on it's way out.

I think a new power supply is the best place to start if you've tested all other components by process of elimination. Hopefully your husband knows what he's doing and he doesn't end up frying the mobo anyway while replacing the power supply.

If a light was flashing some power was being supplied so a PS problem is unlikely. To test the motherboard you will need to take it into a shop.

This isn't entirely accurate. A bad power supply can create a whole host of problems, many of them never resulting in a loss of power.

Irene: You should elaborate more on "flashing light" and "Still no power". These contradict, unless "flashing light" was the last thing you saw before the machine completely died.

Tell your husband to open the unit and look for any misplaced or lose screws. Also check for a burnt smell or any burn marks around components.

That was my point. If a light is flashing, then the PC is getting some power. Yes its possible that some of the leads are working and others not working. Or the PS is supplying power erratically, But those are unusual circumstances. So a PS problem is "unlikely" as I said.