Displays are scanned, not lit steadily
Only one digit line is high at a time; the processor fills the segment lines for each digit in turn (or blanks them) and scans each digit about 61 times a second.
Systems
Related tips
- Display fault: board or display?
- Never plug displays with the power on
- Which CPU chips run the displays
- Power supply bring-up, step 3: displays
- Missing segment on one or more score displays
- Missing digit on one or more score displays
- Displays never show the digit 1
- Wrong-looking digits or bad "1"s
Source: Troubleshooting Gottlieb Displays (On Target technical newsletter, vol. 3 issue 7, 1982), Gottlieb "On Target"