TD700
Burroughs TD700 Self-Scan early gas plasma display screen, with control unit and keyboard, Design Level 4 c1973.
Yay... we have a cursor (of sorts - with a bit of ghosting on rows 4 & 7)) after 4 days slowly notching up the variac to avoid popping old capacitors.
I had already replaced the power socket, a defective mains fuse holder, and 2 corroded capacitors on cards "A" and "T" in the control unit cage. The faint pixels shown up by the cursor occur in the same positions across the row so I'm hoping this may be a resolvable logic or driver issue in the self-scan control card, rather than a write-off self-scan module.
The identity plate is stamped for 240 volts, but the power supply test points for 5.1v, 12v, -12v, 30v, and -250v were all up to required values on 110 volts AC supply from the variac..!
TD700
Burroughs TD700 Self-Scan early gas plasma display screen, with control unit and keyboard, Design Level 4 c1973.
Yay... we have a cursor (of sorts - with a bit of ghosting on rows 4 & 7)) after 4 days slowly notching up the variac to avoid popping old capacitors.
I had already replaced the power socket, a defective mains fuse holder, and 2 corroded capacitors on cards "A" and "T" in the control unit cage. The faint pixels shown up by the cursor occur in the same positions across the row so I'm hoping this may be a resolvable logic or driver issue in the self-scan control card, rather than a write-off self-scan module.
The identity plate is stamped for 240 volts, but the power supply test points for 5.1v, 12v, -12v, 30v, and -250v were all up to required values on 110 volts AC supply from the variac..!