PDP-11/45 RSTS/E boot problem

SUCCESS!! Put the M795 out on an extender, loaded 167777 in RKBAR, and had a look around with a logic probe. Narrowed it down to E34 (a 7430 8-input NAND). Pulled, socketed, replaced, and off she goes! I can now successfully boot and run both V6 Unix and RSTS/E V06C from disk. *THAT* was a really fun and rewarding hunt :-) First message in the thread was back on Dec 30, 2018. Lots of debugging and failed DRAM repairs, then the final long assault to this single, failed gate... Thanks to all here for the help and resources, and particular shout-outs for Noel and Paul who gave generously of their time and attention working through the densest bits, both on and off the list. I predict a long happy weekend and a big power bill at the end of the month :-) cheers, --FritzM.