Soon as the lacquer had dried I started to replace the components, using new parts except for inductors L1 and L2, which were still ok so I cleaned the leads up and reused them. I used machined pin socket strips for the socket for U8. As mentioned before R113 (a 2k resistor) was open, and I didn’t have any 2k resistors I used a 2.2k instead. Note that if you change R113 to 2.2k you also must change R16 to 2.2k as well. As long as this is done the board will function normally.
Also with R140, a 20k resistor I just used two 10k resistors in series, as I wasn’t sure if I could change the value of this one. Another small change I made was for the transistor to drive the LED.. I used a BC548 instead of a 2N3904 as I didn’t have a second one of them to use. Notice the orientation of the transistor in the 2nd pic. A BC548 needs to be turned around opposite as the pinouts are different to the original.
Next I replaced the bottom two connectors J3 and J4. after that I was ready to test the board. initially when I tried it on the bench I wasn’t getting the third flash, meaning a bad U8 or its socket. After having a read thru Clays repair guide and finding the table for checking U8s connections I discovered I had no continuity between U8 pins 9/10 to U7 pin 6, which I quickly traced to a tiny crack in the print near U8 pins 9/10 that I repaired by soldering some fine wire (last pic). Fixing this had the board booting up correctly! (six flashes, no seventh without any 21volts on TP3 of course). All that is left to do now is to fit leads to remote mount that memory battery.
