Today I did a little work on the console printer/keyboard to-be (a Tekade teleprinter used by the German armed forces). The power supply had a problem in the main 5v regulator. This consists of two LM317's in series with an op-amp driven feedback loop. I found out that both LM317's and the op-amp were broken (culprits shown right); possibly an over-current issue. I replaced those parts, and got the juice running again.

The teleprinter is running again (at least, in local mode). To connect it to the pc, I'll either need to build an RS232 to current loop converter, or try to find the V.10 interface card that was an option on these machines.

On the inside, these machines are a pleasure to work with. All functional units (power supply, keyboard, printer) can be removed by unscrewing 2-4 screws. The electronics are contained in a card-cage (three intel 8749 microcontrollers, CMOS logic, and high power transistors to drive the mechanical parts).

Functionally, it's equivalent to a Teletype ASR, with a paper tape punch and reader (except that these are 5-bit baudot code, not 7 or 8 bit ASCII):