The newest plotter in my collection is also a.. calculator? The Sharpgraph EL-7050 plotting calculator could produce circle, line, band, and bar charts on 2.25” paper using the micro Alps mechanism. Anyone have a service manual? #plottertwitter 
Lurking inside is a NiCD 4xAA battery pack that’s typical from 1983. It’s leaking so out it goes. You can also see the Alps DPG-1301 micro plotter mechanism and the power section.
The main board is attached to the top half. Logic on the bottom, membrane keypad and LCD display on top. A few bodges and trace cuts that seem to be interrupting ground. I wonder why?
The plotter initializes properly and the screen comes up. But it isn’t responsive. I’ve cleaned and tested the keypad membrane and PCB and they are fine. I need to locate a service manual. Any ideas?
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