Question HD6870 Vapor-X goes black screen randomly ?

[s0nicx]

I have this HD6870 Vapor-X for 3 years. I mostly use it on my old PC for gaming and mostly playing CS:GO. I never really had trouble with the card, but recently it started to become problematic. First, the HDMI port started to fail which is not much of a trouble as I just switched to the DVI port and it was working just fine for couple months. Recently it started to randomly cause black screen issues. The first time this happens I though the GPU is pretty much dead so I just throw it away and replaced it with another. However I am gonna need the card urgently at this point so I've been reading about this issue for the past 2 days.

I tried to re-install the card and it was working just fine until I started to install the drivers. Once the driver is getting installed ( the moment when your screen start to flicker ) it just goes black forever. Running the system under safe mode works fine. I tried to use DDUC in safe to mode to completely uninstall the drivers and the attempted to install them again. It worked on the 5th try and it was working for like a week when suddenly while I was playing CS:GO it caused some black lines all over the screen then the screen goes black and boom, same issue. I tried the same way as before with the safe mode DDUC, but that never worked again.

At this point I didn't care much about the card anymore because I was sure it's 100% dead, but I tried to disassemble the card and clean it using toothbrush and isopropyl alcohol. I used soft brush followed by hard brush and cleaned up basically every part of the GPU. I don't have a heat gun, so I used hair dryer to completely dry the card. I was sure that I killed it, but surprisingly it worked! Driver installation was successful and I was playing games with the card normally. Again, it worked for a couple of days and the it caused this black screen issue again. I did the same thing cleaning the card with isopropyl alcohol and it now works fine again. My question is what can cause this issue? Obviously the card isn't dead, but there is some problem with it. Wondering if it's possible to fix this for good. Thanks for the answers.

 

[s0nicx]

So just little update here. The card was working fine since today. Surprisingly it crashed while I was playin a browser game ( funny thing it doesn't crash with heavier games such as CS:GO ), but always crash with browser games e.g 8 Ball Pool. I did the cleaning process once again, but since I didn't had any thermal paste left I on cleaned the areas around the middle ( where you apply the thermal past ). Result : Nothing changes, black screen.

At this point I am confident that the issue comes somewhere from the middle. I bought some thermal paste, cleaned the mid part, re-applied the thermal paste and it's not working fine.

Another thing that crashes the card are the recent drivers ( especially crimson beta version ). Currently using driver version 14.4 for Windows 8 x64 which works well with Windows 10 / 1703

Changing my power plan to high performance also seems to cause some issues, so I am currently using balanced plan.

Result: Playing CS:GO for couple hours already, no issues at all. No black screen and not even the usual glitches from time to time.

For anyone that's having the same issues, save couple days and follow my work through.