Went over to a mates place today for a bash and he asked me to look at his T2 where when the start button light is connected you get 2 lamps lighting at once.

Went through single lamp tests and found if I had the start light installed then I would get it light up more than once during the test. Ended up finding a pattern that lamp 84 (start) would also light 74, 85 would also light 75, 86 lights also 76 and 87 lights also 77 and 88 lights 78. The opposite did not occur... Ie 77 did not light 87 and so on. Although from tests 84 to 88 the start lamp was always on. Once the lamp or either lead was removed from the lamp, then everything would work as normal.

Swapped it for another led, same pattern occurred. Tested all diodes of those lamps and they tested fine in circuit. We also tested the power driver board and mpu in a different machine and lamps all test fine.

Any suggestions on what else to look for or reasons why switches 81 to 83 don't demonstrate the same behaviour (ie: they don't trigger 71-73)?

IMG_20190309_120119_resized_20190310_083557727 (resized).jpg