<I guess I must have just gotten lucky to get it to boot those two times. <This is what the machine does <most> of the time. < <KDF11B-BE ROM V0.9 < < 512KB MEMORY <9 STEP MEMORY TEST < STEP 1 2 ERR RAP <173714 <@ 173714 is the address at which the boot selftest program failed. not in ram as 173xxx, is the boot/room page. The count down is each specific test either you get a memeory test error something else. Assumeing the board and rom are ones I know a stop at that address means a NO was types on the terminal duriing console test! To be sure we'd need to know the board handle numbers and rom numbers. to gove that answer I assumed 11/23+ M8189 cpu card, but the message appears to be for an 11/23B cpu/rom set. My guess is you have a bum tube! Also don't apply PC troubleshooting rules to a PDP-11, you'll make youself nuts! <Does this mean that the ram card is bad at a given location? If so, there <is no reason I can't replace the ram on the card with a desoldering iron. <I would like to socketize the ram but I don't think there is enough room <between cards to make that happen so I'll have to solder them directly to <the board and pray I have no more failures. You can, it's possible, you have no clue yeat if it's bad ram. <Is the above 6digit number the location of the failed bit/byte of memory? No, it's a location in rom where the program failed. Allison