Quoted from DumbAss:Visit the pinwiki page. Scroll down a little further to the paragraph titled "Quick Test of Lamp Column Transistors". It will be a continuity test (not a diode test) that you will do on Q91. If the transistor is shorted (continuous) then it's bad. You will need to replace it. I'll bet you a virtual beer that it's shorted.
So this is going to sound conceited but for the most part you can't visually inspect electrical components to verify their functionality. You need a multimeter. I've only ever once visually inspected a transistor and said ... yep that's bad.
All the lamps in the lamp matrix have a diode. They must have a diode. The diode may not be visible as diodes connected to a lamp socket tab. For the most part, the diodes are on the lamp boards.
Ah so this was what I was doing around Q91 last night. Although i was just testing middle leg to the two outer legs, i was testing for continuity... and they checked out with no continuity.. however i did rush it, so i will check again..
For diodes, I couldn't ID any of the ones for the cabinet switches (lit buttons) and all the lit buttons are what are staying on (column
You are totally correct about electrical components and yes I have to get better at testing... of all the 4 games i have repaired, its been a moderate refresh as the boards have been known-good but it turns out my luck has run out!
pinside needs more virtual beer buttons...