Just got a replacement CPU which is confirmed working. Sadly the ZXM GS still doesn't work
Quarz is 12MHz, Firmware 1.02 12MHz, gs105a.rom, CPU is a Z84C0010VEC (I know it's overclocked, but the CPU stays absolutely cold)
Whenever I try to load a programm which uses the GS the whole computer hangs.
EPM7128STC100 is the -15 variant, for the ROM I'm using an SST 39SF010A-70, Power is provided via the molex connector on the card.

Host computer is a ZS Scorpion 256 Turbo+ with ProfROM using a real floppy (same issues when using a SMUC). I'm using the outmost ZX Bus slot at the edge of the computer.

Any ideas or other things to check?