Well the Retro-Printer was officially launched on 16th January 2019.
We have however, had to temporarily withdraw it from sale, as some users had reported issues with it draining the power from the Raspberry Pi when connected to centronics equipment.
It appears that the factory managed to get their numbering of the pins 19 to 36 back to front on the PCB (it is correct in their schematic), which meant that 5V was being delivered to pin 13 (SELECT) and pin 25 (which should be GND according to the specification), instead of pin 13 and pin 32 (ERROR). Because the other pins on the bottom row are normally unused (or connected to GND), it was not obvious that anything was amiss during our in-house testing.
This does explain why removing the diode D1 fixed the issue for some users and some users did not experience the issue at all.
We are talking with the factory to see what is the best way of resolving this issue - obviously one way is to re-wire your centronics cable to reverse the wiring on pins 19 to 36, but that is not always possible.
