Did you ever figure out what was causing this?

I just picked up a great condition Taxi, everything is 100% except it won't hold HS memory for more than about 15 minutes before it "forgets" them! I'd love to get a head start on fixing it.

Thanks dewdude! I meant to post back on this thread, I found the problem it was the ground switch wire that triggers the HS reset - which had become unsoldered to the switch and was randomly grounding out against the case.

Now, I've just got to figure out which chip burned up that's causing this:
2014-04-28 21.08.58.jpg

I've got several segments constantly lit. I blew it up again (HS 10.6 mils!) and when it was flashing and whooping and going bonkers, those segments lit up and haven't gone away. I knew something got juiced at max voltage and burnt out, I just am not sure which chip controls those segments. The one on the upper left only shows up when the Jackpot score is lit and flashing. I'm pretty sure whatever controls that particular segment needs replacing.

Anyone who might have some insight, I'm all ears!!

Thanks dewdude!! That points me in the right direction. I have the full service manual and schematics, so I'll take a look. I also have Police Force sitting right next to Taxi, so I can swap displays and parts as need to diagnose. Funny, those are two of the only machines to use that split dual LED and extra 7 segment slave display! Lucky for me PF is in perfect shape so I have a great side-by-side comparison.

Ah, that helps tremendously dewdude!

Big thanks, I'm going to start there are see what I find on the display board. Hoping that I can replace a chop or two and not have to kick out for an entire display board. If I hafta, I hafta. Won't be the end of the world to put a new Rottendog display in there. I did, however, just spend nearly $250 on rubbers, plastics, and a replacement right side ramp that I and the wife is giving me the stink eye about it. If I try to run a LED display up the flagpole with her, I'm likely to be drawn and quartered!!