Given that the system seems to pass a lot of diags, but fails the LTC test, I'm focusing there. From looking in the programming manual for the DL11-W, it appears that bit 7 never being set means that there is no LTC L signal coming in to the DL11-W. It would appear that software clears this bit and then waits for it to set (by the square wave from the AC at 50 or 60 hz or so). According to the diag, bit 7 never sets, so I'm thinking I'm not getting any LTC signal from the power supply. I need to find that square wave signal and see if it's working and directed to the right place. My problem is finding that signal. My 11/45 is a KB11-A, serial number < 2000. The maintenance manual shows the LTC coming from the power supply to the power distribution board (top connector towards the cabinet door) shows six wires, the bottom one (brown) going to slot 1 row C where the M787 option plugs in. My top connector does not have that many wires, only 3 or so. My system never had (I don't believe) a M787 card. The system came with two DL11-A (M7800), and a M7228 (KW11-P). But I don't think there was ever a LTC in slot 1. So is it possible that LTC isn't even routed out of the power supply? I'm wanting to use a single DL11-W with the onboard LTC. But doesn't that need to get the LTC signal from the backplane? If it wasn't ever routed to the system unit.... So I'm not sure where to look. I'll pour over the manuals some more. Jay West