OG Xbox 128mb Upgrade

Hi guys. I am trying to do a 128mb upgrade on my OG Xbox and so far its not going well. I have soldered 5 different chips on the board to test, 3 recovered from old xboxs and 2 brand new ones and none seem to work.

I have checked for bridges on each one and also checked every leg is soldered and yet they still will not show up as working in Xblast OS.

I am starting to think the bios may be the issue? I installed the 256k ind-bios 5004 F+G from the Hexen 2019 disc.

Any help would be much appreciated because at this point I am about to give up :(

Thanks.