Leaderboard

I don't know this game but do the reels spin (index) when it's switched on? Most MPU3 games I've seen the reels spin on switch on and again if the door is opened or closed and if the 'test' button is pressed. If this one doesn't (at switch on anyway) I suspect the lamps sensors aren't working which may explain why you get the error with the reels disconnected. Can you confirm the 4 lamps are coming on as if not it's likely T55 has failed (BCX38). You do say emitter OK, does that mean the lamps? Bon courage.

What software did you build your board on? The realisation is great from when you used to play the games back in the day- to hitting the button to order your pcbs, tracking them hourly all the way from China and then self congratulating when you find out they actually work 😅

It's funny how the legs fall off of those liquorice allsort caps.

I tested the machine with another board to be certain and you are right Magik. I'm afraid I don't have a logic probe. I did a multimeter diode test which didn't help on the lamp transistors, but across the collector and emitter of T1 to T8 gave a reading of 0.6 in one direction and 1.8 in the other on all except on T3 - gave zero I did the same test on a known working board and all transistors gave the same results - give or take. I replaced this transistor T3 and the 2 lamp transistors that it connects to, T47 and T55 and it now boots, but several of the lamps are very bright and some flicker. The PSU has already been overhauled with new caps Is it now likely to be a faulty diode in a lamp holder that I guess then overloads the circuit and burns out the transistors?