On my ASR-33 Looks like it may be a bad transistor in the receive
circuit....
Basis for conclusion:
1) switching keyboard units has no effect.
2) disconnecting reader unit has no effect
That is to be expected if pressing a key doesn't cause the distributor to
rotate. What happens if you press the armature on the magnet at the rear
right of the typing unit (the one with the black and white wires, on top
of the transmit clutch area?
3) R7 on receive control bord is HOT (to the touch)
4) Selector magnet appears always engaged.
It should be.
5) Unit does NOT space-out when put in line mode.
As it spaces out when you press break, I think the driver is working.
-tony