*** M E M O R U M ***

I've got some 4116 chips from retroleum.co.uk. They appear to be TMS4116-15NL so according to http://www.primrosebank.net/computers/m ... txvram.htm they should be fast enough.

I'm reading through the service manual and also http://www.primrosebank.net/computers/m ... repair.htm and http://www.primrosebank.net/computers/m ... _fault.htm

Good luck!

Victory!

I ended up replacing 3 4116s. I tried checking for overheating chips but didn't feel any obvious differences. I ended up grounding pin 14 of each VRAM chip in turn via a 15 ohm resister and found 3 with dodgy bits. De-soldered those, fitted some sockets and it worked first time with the replacement 4116s.

Thanks Dave and everyone else for the help and encouragement!

Wishing you all a Happy New Year!

Happy New Year to you too.

Great stuff - well done!

What he ^ (Dave) said.

Well done

Mark

4116 chips are always dodgy!