Ram upgrade issues

[UnderTheRain]

I'll have a bit more time on the weekend but I have metered the connections out and vcc/Ov are good all the ras/cas lines goto the resistors and then to the mmu, as do the address lines. The data lines all meter to the 74LS373's and the we is also metered to the mmu I i'll try totally removing the roms and reseating them and/or try the ones out of my other fm and maybe the mmu also. I checked the data lines and the mmu and 68k seems to all be there. I haven't recapped the psu yet but it's on my list again I could try the one out of the other FM (but that needs capping/replacing also).

It's fun though

Thanks

Brian

[UnderTheRain]

Just thought I'd post a quick update

Recapped the PSU
Re-seated the ROM's with some contact cleaner
Re-seated the MMU pulling all the pins out with tweezers and contact cleaner

And SHE'S ALIVE!!!!! Muahahahaha!!!!!

Thanks for the pointers guys

Biran

[Icky]

always good to see life again in these old beasts.

[exxos]

[UnderTheRain]

Forgot to add this photo might as well. Added a small switch the 1-4mb selector should I ever need it.

Brian

L1643226038187_IMG_20220126_194038.jpg (298.55 KiB) Viewed 2645 times

[rubber_jonnie]

Glad to hear you're all up and running



There can be fallout after Marpets due to the way they connect to the MMU socket, so it's always good to check the sockets afterwards.

As for the other socketed ICs, they can easily shift due to handling of the board, so a reseat of anything in a socket is always a good thing.