R9 280x problem diagnostic?

[liomojo1]

Well I have 6 x 280x , i modded the timings of the ram with tahititiming mod! It was ok , but after 10 min of mining one card started too fail , I flashed the original bios back to all cards , but one this card remain to make trouble , 0hashrate and windows crashing! When i removed it everything was ok! Now with the original bios it works OK and have  enter windows but only if the driver is not installed. When i install the driver , the screen gets all in blue white lines and pc crashes. Now i flashed custom bios with 500mhz core and 150mhz ram. It is working perfectly even hashes with no errors and i can rum 3d benchmarks! When i up the core to 900 with msi afterburn everything is ok , but if i up the ram more than 420mhz it starts to give artifacts and the nice carpet screen! So my question is what could be wrong ? Now it is hashing with claymore miner at core 800(real, default is 1070) and ram 400mhz(reall clock not +400, default is 1500) at the speed of 26sol/s and have no issue , i run
    Video Memory stress Test v1.7 and there no errors?
What could be wrong , ram or gpu is failing?

[StanchoBS]

I have same problem with claymore 3.0 , but 3.1 work fine now. Dont know why

[adaseb]

Just reflash your original bios back. Or use bios switch.

[liomojo1]

It is not the miner it is my hardware , but if someone can guess what to repair , is a ram issue or gpu is dying or i don`t know?
I reflashed the  old bios 10 times but no improvement and there is no bios swich on this card !Asus direct cu II

[adaseb]

It is not the miner it is my hardware , but if someone can guess what to repair , is a ram issue or gpu is dying or i don`t know?

Your flash failed just reflash it again.

What GPU is it?

[liomojo1]

It is not the miner it is my hardware , but if someone can guess what to repair , is a ram issue or gpu is dying or i don`t know?

Your flash failed just reflash it again.

What GPU is it?

I reflashed the  old bios 10 times but no improvement and there is no bios swich on this card !Asus direct cu II r9 280x.
I made my self this custom bios with this low mhz , cause it  could`t start with drivers installed!

[StanchoBS]

Try to reinstall windows and use original bios for first test. Try with only claymore 3.1 for zcash, im sure 3.0 its not working fine. This working for me (maybe i changed slot or cable), and i switched back to original bios for all my 280x. 55H is enought for me

[adaseb]

Try with another slot and do a regular gaming benchmark.

Impossible to damage GPU with modified memory straps unless you messed with your VRMs voltages, etc.