Hi Folks, I'm a new member but I've gratefully read your advice in the past when fiddling with a couple of polys.
I have a problem with an 'as-is' MkI that I bought on ebay - three of the 7-segment digits don't work at all. Reading L-R, It's the 3rd, 5th and 6th.
I've replaced the 7-segment displays themselves, and checked the cables. There was extensive corrosion from a battery leak on several of the boards and it was very erratic when i first turned it on, but thankfully after a clean-up everything else seems to be working fine
There's some weird crosstalk going on between the digits, with kind of 'ghosting' of the non-working 3rd digit on the 4th display. Before I cleaned the board, there was even weirder stuff going on with crosstalk.
I've ordered a replacement IC30 (BA618) LED driver and IC31 (M54513) darlington array. My basic electronics ability is ok, but honestly my troubleshooting and testing isn't the best. So I just wanted to check whether any of you folks had any suggestions or advice on sources of the problem that I might have missed, or whether I'm totally on the wrong track.
Any advice very much appreciated!
Andrew