HP-67 stuck in scientific (DSP 0) mode

[teenix]

I'm trying to think how this can be in a multiplexed display. The segment can only come on if powered by the anode driver when the cathode driver is active low on that digit. The faulty digit is in a separate LED module to the first digits so unlikely to be an internal short.

If the cathode driver had a faulty output that segment may light, but only if the same segment was lit on another digit, which is why I suggested entering a number that changed the lighting of that segment on other displays, as it might have change the faulty one.

It appears to be linked to a decimal point because the W/PGM display doesn't use one.

What happens if you key in [f] [-x-] in RUN mode?

This flashes the decimal point and might flash the faulty digit.

cheers

Tony