After successfully repairing the G231 module of the MM11-L set I continued with the next one. This one was not able to access addresses ending 0100 (binary). Luckily it was not the transistors arrays that were bad but the selector chip. A Signetics N8251 chip.
I found a source on ebay at $4.95 each plus $13 shipping. A little bit to much for my taste (although I could make an offer) Anyone know of a cheaper source? I could use five or ten maybe. /Mattis