Similar to HP 46 ??
|
03-27-2015, 04:44 PM
Post: #22
|
|||
|
|||
RE: Similar to HP 46 ??
I have decided that the printer itself is OK. The print drum spins. I can cause the paper to advance. I can raise the two color print ribbon. I can selectively operate all of the hammers. I know that the calculator functions normally in the display mode. Each of the printer functions mentioned above is preceded by what looks like RCA TTL logic circuits 1820-0946. I am searching for a data sheet for this chip which one source identified as a positive NOR gate. After I find the pin-out for this chip, I can check the inputs and outputs to see why it is not activating the transistor drivers for the hammers. Since all printer functions are affected, I suspect an over-all inhibit input which could even be coming from the keyboard printer on/off switch. But, I've got to work my way back systematically.
Rich |
|||
« Next Oldest | Next Newest »
|
User(s) browsing this thread: 1 Guest(s)