cant seem to flash my sapphire nitro+ rx 480's

hello good people of this forum .

a while ago I flashed a r9 290 to a 390 or 390x doing 350mh sols flashed it successfully , and i bricked my cards 4 or 5 times already , 1 time both bios;es on 1 card , my 2 stock sapphire nitro+ rx 480's give me around 280sols with 1332 core clock and 2200 on the memory .

I really have trouble finding a proper rom for my gpu , gpu-z says that its using Samsung memory .
the meminfo tool of asus don't work on my system , all fields are blank .

I tried several roms , I flashed the roms all with no oc enabled , and all display drivers wiped , most of the time i flashed via a dos usb key or admin cmd , or just with atiflash , and had no success , 1 of the roms what this 1

https://forum.ethereum.org/discussion/9650/sapphire-rx-480-nitro-oc-8gb-11260-01-20g-modded-bios-29-mh-downvolt/p1

and a v4 bios wich worked for some people with Samsung memory but not for me , and I also tried all the nitro+ 8gb roms not the oc from techpower up wich also doesn't work on my gpu's , I really want to flash the bioses like with my r9 290 for a increase of hashrate and overclockability , I know its possible , but am I missing something while flashing the bios ?

here are some screens :









please can someone help me out ?

tnx in advance !