Bit of GOLD BALL attention needed tonight,
@Nedreud is going to visit soon for an inspection so all must be tip top.
The top L and Y lane feature lights have been intermittently sticking on and increasingly so- fortunately when I got the machine the P and A lights were stuck on so I had a fair idea where to start. Referring to the manual these are both driven by SCR Q22 on the lamp/solenoid driver board, that's this fella and the SCR bank is top left. On this machine a single SCR drives a pair of feature lamps on two phases 0A and 0B.
The SCR tested ok per the rest in the bank, but as it was an intermittent problem and I had one in my spares thought it was worth swapping out first anyway. Also wanted an opportunity to replace the PCB stand offs and fill any missing with those I got recently from
@myPinballs. This must be what Jim was talking about - spot the new one!
With the board out the plane behind looks like this which appears shiny but on closer inspection is like a foil covered cardboard - note new stand offs in position, the PCB attaches by these and bolts to ground points in both corners.
Q22 replaced and PCB back in - note white stand offs poking through
Problem fixed! L and Y lights now switched OFF when they should be.