Question Computer boots and works, but no signal to the monitor, only posts on MB video output

[Rhyynoe]

Hi Everyone,

For a few months, every now and then when I turn on my computer for the first time that day, it doesn't post to my monitor and comes up with no signal, everything works and I can even log in and let my computer start everything thing up (i can tell by listening to notification sounds and stuff that come up after typing in my password). I can then just shut off my computer, turn it back on and it's fine, no issues whatsoever. But today, the same turn on and no post happened, but it didn't resolve itself after restarting. I am unsure what the problem is but have tried many things:

• Restarting many times (it worked well before but nothing happened this time)
• Reseating the GPU
• Checking that all the cables are seated properly
• Looking for any peculiar things on the motherboard etc.
• Changing around the places the PCIe cables are plugged into the power supply

I then decided to completely remove the GPU and run the monitor off of my MB/CPU graphics, and it works completely fine, no startup issues at all. I then put my GPU back into the computer without using it as an output and the computer still worked as if it wasn't even there. When going into Speccy, the GPU isn't recognized at all. That leads me to think my GPU is gone but there is power going to it but there's no video output from the GPU. The GPU also makes a high pitched and continuous hum a few seconds after booting up. The fans on the GPU cooler are also acting out as it seems to use the 'power saver' thing where it only uses one fan till it gets hot, but the second fan will turn on and off over and over again. My friend had a similar problem with his GPU fans and that turned out to be a PSU problem.

I don't really expect a perfect fix (cause I don't think those exist for computer issues as most seem unique) but I'd really appreciate some opinions on what the issue might be so I can figure out what components I need to replace or what not. I don't want to go out and buy new GPU and then it turns out it was something else. Most of my computer is old hardware (3+ years) so maybe its just time to upgrade?


My PC:

CPU: i7 6700K (not overclocked)
RAM: 32GB DDR4 @1066MHz (seems kinda low, but its old ram)
GPU: GALAX GTX 970 exoc "4GB"
PSU: Antec 700W
OS; Windows 10 Home

 

[DSzymborski]

That the GPU is making an odd sound while not showing a display is concerning. The PSU ought to be sufficient. You're likely out of warranty on the 970, so I'd probably try swapping in another PSU first, even though I think the GPU failing is more likely; you can always use a spare PSU and they're pretty easy to return while I'd hate to get you buying a new GPU if your current one actually works.

 

[Rhyynoe]

Thanks for the reply,

I'll try another PSU tomorrow, I have a few spares from my uncle's computers so I'll give that a go.

 

[DSzymborski]

Thanks for the reply,

I'll try another PSU tomorrow, I have a few spares from my uncle's computers so I'll give that a go.

Good, it's always useful to have a spare around for this purpose. Though be mindful of the quality of the PSUs; some random PSUs may be fine for simple testing, but not for running the GPU at full load.

 

[Rhyynoe]

Ok, I'm really annoyed this morning for the wrong reason because before I tried a new PSU I thought, why not put the GPU in one last time to see if leaving it overnight did something. It did do something. I reseated the GPU the exact same way I did the previous 3 times and now it works, the only foreseeable thing that would be any different is the order in which the wires that go to the GPU were put into the GPU (the type of wire that has a 6 pin and an optional 2 pin attached, there were 2 of them to go to it and I only needed a 6 pin and an 8 pin. So I changed which 6 pin had the 2 pin with it.) I highly doubt the issue has magically resolved because the issue was on and off for a while before this but for now it seems to be fine after a few restarts. If anyone has any idea as to what caused this feel free to reply because I'd like to stop it from happening again.