开云体育

Hello Jim,

I owed and restored a 464 with DM44 (now given to a friend) and I don't think there are any other "optional" boards linked to the presence (or absence) of the DM44.
The only optional boards that apply to the 464 / 466 are:
A. The optional DC inverter board (option 7)... That one can't co-exist with the DM44 (the inverter uses the same windings on the main transformer that are used to power the DM44).
B. The composite video Sync Separator (Option 5), which bears some relation to the A5 sync board and could explain some changes.

I did hear once, from someone of this group, there was two versions of the A5 Sync board... one that used the Tunnel Diodes, and another one which used a Custom Tek IC to discriminate the trigger edge.
I`m not sure, but maybe this is what the -01 means...
I've never landed my eyes, however, on a schematic of the latter, or a later manual that included both.

But regardless of this board versioning, It seems rather odd to me that the connections to the J6 are disconnected, and more so, that there is no connection between the top and bottom side THROGUHOUT the board...
Moreover, there's nothing about the DM44 vs power to the A5 Trigger board... The DM44 takes its power from its own power supply and it's neither fed by the A5 board, nor the A5 board feeds it.
Yet, the only reason I can think of for the through hole plating is missing throughout the board is, either a mass murderer technician stripped them off by careless unsoldering, or yet, that it's a prototype board...
If it's the latter case, it could explain many things...
Maybe you can take a picture, post somewhere and link it here.

KRgrds,

Fabio