Ok, thanks for everyone's help, here is what I've discovered so far. First off with the unit on and under load, the power supply is +5.23, +12.04 and -5.03. So they seem fine though the +5 is a little high. I took out the 90 degree cartridge adapter and it was very dirty. I cleaned it with 99% isopropyl, sprayed Deoxit on the connectors and the MB connector. However still no joy. All my other cartridges work fine but the FinalGrom still never shows up. I then tried bypassing the 90 degree adapter and plugging the cartridges into the MB directly (I checked and cartridge bottom traces face the rear of the machine) and nothing worked then. I just get a continuous tone no matter what I plug in there. But if I put the adapter back in regular carts work again but still no FinalGrom. I turn the TI on, press the left hand blinking button on the FinalGrom, and all I see show up is TI Basic. So maybe it is a timing difference etc between my 2 machines but at least 1 TI works fine with the FinalGrom. Guess I know which one is the spare.