My advice for anybody doing any sort of upgrades is to only do only one thing at a time. Easy to say retrospectively I know!
Upgrade the RAM, test and if all is well, add the Blitter socket. If it doesn't work then you only have one thing to try and troubleshoot.
I know how easy it is to get caught in the moment and do everything at once, I've been there myself. Glad to hear you've got there in the end
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
I know, I know... But the socket was a passive component... how could that possibly hurt?
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.