I need help with solving a really strange problem

[addicted44]

So I'm gonna start from the beginning : I renewed my PC build about 9 months ago and everything was fine and dandy. But about 1-2 weeks ago I started having this weird problem. Everything is powered and working fine, fans work, but my system freezes and loses video signal and I still see that all my fans are working and the system is powered and doesn't do anything. On the headphones I still hear my game or whatever is running on loop like it's frozen. I tried testing for overheating and my CPU runs at ~68 degrees C and GPU at about 60~. Tried removing RAM, cleaning it with alcohol and putting it back. Tried reinstalling a fresh new OS (changed from Win 10 to Win 7) still nothing. It happens completely on random even sometimes I just booted the system and it happens. I tried yesterday to force constant GPU voltage through Afterburner and everything was fine for about 36 hours and then it started doing the "no signal" thing again. Also cleaned the whole case from dust and removing the GPU and plugging it back in.
Things I have not tried but consider trying although everything seems really desperate at the moment :
Flashing BIOS
Cleaning GPU connector.
Memcheck
Full PC specs :
GA-H110M-S2
Intel i7-6700 @3.4ghz
Sapphire Dual-X R9 270x @ factory settings
A-Data DDR3 2x4 GB @1600 MHz
Intel 500 series SSD 120 GB
really old Seagate Barracuda : 300 GB
The only error I've found is this : Driver ACPI returned invalid ID for a child device (5). I've tried most of the suggested things I could find. Also when the PC loses signal and I reboot it when it loads Windows it doesn't get the signal back (the motherboard and windows loading is fine and displayed but when it goes into windows still no signal even after reboot) so I have to unplug the PC fully and wait 10~ seconds then it boots normally. It happens mostly while gaming but has happened once while not doing anything stressing to the PC. Please give any ideas and sorry if I posted in the wrong category (didn't know which one is the right one since I don't know the root of the problem).

[hazmi]

Try use Onboard Graphics or another GPU gpu.

[addicted44]

Using another GPU proved that it was GPU bound. But can anyone suggest how I can save my current GPU because I don't have a lot of money right now to spend on a new one

[thunderbuzzard]

sorry for reviving the thread, I'm in the same boat as you are right now l, waiting for my friend to get back from abroad so we can exchange gpus and see if the gpu is the issue "I really wish it is" I'm itching to go grab an rx550 for testing but I don't want to spend a penny unless I'm sure of what source of problem is. if your gpu still under Warrenty contact thr store or the manufacturer if ur a few months out of the Warrenty there are those rare instances that they can help you replace it even at a small cost.