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.
Youch!
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!
Nine months later, I decided to get a $45 refurbished motherboard from Newegg, and swapped it in. Thermal goo application, haven’t done that since about 2004. Anyway, my diagnosis was correct – it was a dead mobo. Computer is working again, yay!
Edit: Sadly, not out of the woods yet. The computer boots but runs really hot – 55-65C idling, and evidently so hot during gaming that it shuts down after a few minutes (happened twice). Tried cleaning/reapplying the thermal goo using the ‘dot’ method (put a dot in the center of the CPU and let the heatsink smoosh it around evenly) but this didn’t make a noticeable improvement. I was using bog standard Insignia goo from Best Buy ($3.50); I don’t know how good that stuff is. I do have some Arctic Silver coming from Newegg but I’m skeptical if that will make enough of a difference. My computer always ran hot, but not like this.
This sounds suspicously like what we just went through for my son’s pc. Remounted, got a new heatsink / fan, nothing really worked for any length of time.
I wrote it off to a bad CPU, as it was about 10 yrs old. CPUs are designed to compensate by putting more voltage through when they start detecting problems.
CPU fried the motherboard. CPU is bad.
Sounds like that could be a possibility. Does the CPU heatsink feel hot to the touch? Is the fan spinning at max? Maybe a bad cpu temperature sensor?
I’m sure electron migration has messed up the cpu.
CPU fried the first motherboard, or the second motherboard? The computer is running now, but running hot. Is that consistent with a ‘bad CPU’? I would have thought a ‘bad CPU’ wouldn’t run at all.
Yes a cpu with electron migration will run hot and can damage a motherboard. It takes time to damage the motherboard it’s on. Has happened to me many times in the past.
Is there any way to diagnose electron migration without waiting for failure or assuming the worst? I’ve never heard of this before.
The only other possibility is if your heat sink is broken. But I’m guessing you’ve already ruled that out. The way to diagnose it, is what you’re dealing with right now (or run Prime95 and look for errors). But I would highly suggest you not run Prime95 because you will most definitely overheat and kill it with those temps.
Electron migration is always happening. No cpu lasts forever. It’s dealing with the rate of that migration over time that determines how well a cpu holds up. When a cpu is overclocked or overheated you significantly increase the rate of electron migration that occurs. It’s also one of the reasons you don’t want to buy video cards that were bitcoin miners.
Well, the computer first crapped out in February, after about 6 1/4 years of use, for what that data point is worth.
I know this doesn’t help, but I remember using thermal paste that came with a vinyl cutout and a plastic card. You put the vinyl on the CPU, placed the paste in the center and smoothed it out with the card. It pretty much put exactly the right amount of paste on the CPU.
Looks like the problem was the stock heatsink/fan that was installed when I bought the computer. It had always run loud and hot. I swapped it out for a Noctua NH-U12S (dang, that’s a big heatsink) and reapplied thermal goo, this time Arctic Silver 5. Afterward the PC was running about 40C cooler than before, and I put it through some gaming paces last night. CPU only peaked at 47 after some Doom and Wolfenstein: The New Order, as opposed to >80 when idling before the cooler upgrade. As a bonus, it’s much quieter.
So, I’m cautiously optimistic that this PC has been salvaged, although the real test of cooling will come in the summertime.