I found the table to interpret the LEDs, buried around page 256 of the KDF11-BA manual. It told me that 0011 is: waiting for SLU Transmit. Odd, since there's no handshaking on the console lines :) That pointed me immediately to the console serial port, since I already knew the VT220 and cable were working via the loopback test. It didn't take long to discover (with my trusty Tek 545) that there was no clock on either UART in transmit or receive. The 5.0688 MHz oscillator was working (surprisingly - I figured the recent move had broken the crystal), and its signal appeared normal at jumper J21/20. But there was barely a wiggle on the two gates that it connected to. Poor continuity also, which improved when pushing sideways on wirewrap pin J21. Close visual inspection with bright light and magnifying glass didn't show much. I resoldered the pins and voila - RUN light on, startup message on terminal, booted from DL0: etc. So it was just a bad factory solder joint from the 1980's... Sorry I panicked :) -Charles