I found the problem with my non-booting PDP-11. I feel incredibly stupid so I thought I would share my findings and hope some of you have done something equally dumb ;) This morning I traced the BHALT L line to the KDF11-BA's edge finger (AP1) and confirmed that it was indeed low all the time, as I had earlier posted. Measured at the front panel it was still low. So I flipped the HALT switch to the other (up) position and sure enough the line went high. I toggled RESTART and the RUN light came on. I heard a "bump" (nonprinting character) on the teletype console but nothing else printed and then ODT came up at 173546. Another look at the switch settings and turned off the turnkey mode in favor of console dialog mode. Still just a nonprint character at first, but after waiting a few more seconds, sure enough "TESTING MEMORY" printed out. It took several minutes to test the big Clearpoint board (I had miscounted the chips, it's the maximum 4 MBytes/2 MWord) and then printed the correct "2044. KW" followed by "START?" which is exactly what a KDF11-BA is supposed to do! :) :) So the defective clock oscillator which seems to be working fine with a 30 MHz replacement was problem 1. Incorrect switch settings on two different versions of KDF11B manuals was #2. But the most recent session of hair-pulling and teeth-gnashing was completely my fault. (In case you haven't figured it out yet, I had been setting the HALT switch in the halted position!!!) RTFM I guess :P Now to fix the FAULT in the RL02 or RLV12 so I can boot from it! A few seconds after entering "Y" to the "START?" prompt, ODT enters at 173526 which is most likely because the controller is not responding properly. Of course I don't know what's on the pack and it may not be bootable... one step at a time. -Charles