While I was playing Toobin, for the review elsewhere on this site, my 128k Spectrum +2 decided to throw a hissy fit and stop working. After several attempts at restarting, resetting and dropping it on the floor from a few inches height (yes, it does work sometimes and fixed the sound on occasions on this Speccy) it still refused to work leaving me with various screens like this one

I have a second 128k +2 but it refuses to play nicely with a PicoDivmmc. Having opened the first +2 up and tried reseating all chips and checked for anything hot without any joy, It was time to ask for help in the Spectrum 4 Ever Facebook group.  It wasn’t long before somebody had replied that the rom chips could be the problem, and that the second was probably the Z80 which could have a missing m1 line (no I don’t know what that even means either but these are some very clever guys). Soon after the diagnosis, a very good deal had been struck with Ian from Mutant Caterpillar games, henceforth known as MCG, for a new and even upgraded rom pair and a Z80 and the parts were on their way.

Once the package from MCG arrived it was time to open up the Spectrums, starting with the missing M1 line Z80. I prized out the cpu and pushed in the replacement, refitted the top part and moved it aside for the rom replacement. The Spectrum 128k +2 comes apart easily, 6 screws underneath and carefully open up and disconnect the tape drive plug and keyboard membranes. It looks like this..

The 2 rom chips are just left of the Z80 in this picture, and socketed so a flat blade screwdriver can be used to carefully lift the two chips from their sockets. Then just as carefully align and fit the new rom chips (eproms written by MCG with custom roms which add some extra features) labelled with ic numbers matching the board silkscreen print. Reconnect everything and test both Speccys.

The roms seem to have fixed my main one, and it loads from the DIV device again and plays games. The second one with new Z80 is still not happy with a DIVMMC plugged in, but otherwise works just fine still. I score that a draw overall.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.