Wednesday, April 6, 2016

Tutorial: getting all the bulbs working

My friend Lee (cdnpinballer) had posted up this great tutorial last year that I wanted to share.
When you get a new game in the shop, how do you get all of the bulbs working?

His response, in regards to his Big Game:

I always start diagnosing non working lamps by trying a fresh new bulb with a few turns of the socket and in my case I had to replace probably 10 burnt out bulbs. If the new bulb doesn't work I then reach for my aligator clips. 

I clip one end to the questional lamp socket and the other end to a working lamp socket. If the lamp turns on then I know the socket and bulb are good. If it doesn't turn on then I know to replace the lamp socket. So, I had to replace a few lamp sockets as well. 

Then I turn to the connector pins on the lamp driver board. I just replace the 0.100" connector pins of the suspect bulbs because it takes a minute or two and it's easy. So, that fixed maybe 2 or 3 broken bulbs. At that point I was left with 4 non working bulbs. 

The only items left in the chain are the transistors, chips, some resistors and possibly broken solder joints on header pins or the header pins themselves. So, I removed the lamp driver board for a closer look. 

Solder looked good, no cold joints. Header pins looked OK. Tested the suspect transistors and 2 of the 4 definately tested bad so changed those along with the other 2 suspects because it doesn't take that long to do and they are cheap. 

With the board reinstalled 2 of the lamps still didn't work in attract mode. WTF? Do I need to replace a chip now? It doesn't make sense because they're driven by different chips. Hummm.. I was stumped until I put thr game into test and everything started flashing. Lesson learned! Not all lamps flash in attract mode! :FP:

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