Computer won't POST


The CPU fan spins. I don’t see any lights on the mobo but not sure if there are supposed to be. I’m gonna see if I can get a look at the user’s manual for it.


I LOL’d.

@Gordon_Cameron It is possible that there is a problem with the PSU even if the fans spin, I see that fairly often here at work with the DELL desktops we use.

Is your PC a pre-built retail model (if so which one) or a home brew (and if so what is the mobo model)? If it’s a retail model, often there are power/indicator lights on the front that will blink or change colors to give you an error code. If it’s home brew, check the mobo for any indicator lights to see if they are on or flashing.

If you have access to a second power supply of around equal or greater capacity, I would recommend connecting it to test the system (no need to install it all the way, just connect the cabling to the mobo and see if it POSTs).

All of this is far easier than buying/replacing a mobo, so may as well try it first.


It’s a prebuilt gaming PC by the now defunct “Avatar” retailer:

Motherboard model:

There are no blinking lights, just a steady blue light that goes on when the PC is running.

I’ll see if I can scare up another power supply.

The good news is I can get one of those mobos for like $80 on Newegg, so if that is the issue, I may not be out too much cash.


So after some more futzing around I have concluded that it is probably a dead mobo, but I cannot categorically rule out a power supply issue even with the fans spinning.

My next steps are to 1) find some guy with a power supply I can swap in to test that, and 2) if that fails, buy a replacement motherboard that is compatible with the CPU.

It’s an old PC, but if all the other bits (graphics card, cpu, hard drive) are still working, it seems a shame to chunk it just based on one $80 part failing. It could still push polygons well enough to run, for instance, Assassin’s Creed Origins. I just need to make sure I get the motherboard from somewhere with a liberal return policy.


This reminds me of when I was a teenager and my 486 motherboard failed. I bought a replacement, and got the bright idea that, “Boy I bet if the BIOS chip in the new motherboard would work in the old motherboard, I could get the old motherboard to work again.” Of course, the new BIOS chip then got toasted and I ended up with two nonfunctional motherboards.




Do you have a retailer near you that sells PSUs, like a MicroCenter or a Fry’s? If so, return policy on those is usually pretty standard, so you could buy one, test your system, and if it’s not the PSU, return it for a full refund. Easy way to rule out the PSU at least.

If you do need a new mobo, I see several GA-78LMT mobos for sale on Ebay in the $50-$60 range, all pre-owned. I’ve had mixed results with Ebay sellers, but usually if you stick to the places that are obviously storefronts with hundreds or thousands of positive reviews you’ll be OK, even if you have to do a return/replacement.

On the other hand, this ASUS mobo brand new on Newegg is only $70. AM3+ and DDR3. Doesn’t have the built-in Radeon 3000, but I assume you were using a GPU card anyway?


Yeah, I had a separate GPU and was thinking of getting a different, compatible Mobo. There is a Fry’s nearby – thanks for the tip!