beerorkid
New member
assistance on next path for stuck on lights - baby pacman
Got a baby pacman a bit ago and am working on getting all the lights on the playfield working. I replaced a lot of bulbs and have found an issue with two lights that are wired together that remain on at all times.
From reading over the pinrepair page on BPM it seems I must have a bad transistor (think that is the right terminology)
I am thinking it must be a 2N5060 that is causing the problem on the lamp/solenoid driver board causing the issue.
I looked over the manual. Link (hosting it myself for faster DL) and it does not seem as informational as the ones for my other pinballs. I cant seem to figure out which transistor it might be that corresponds to the lights messed up.
The 2 and the A I am pointing at in the 2nd row are the ones that stay turned on constantly.
bottom view
Lamp board. (can get better pic if needed. Pretty much just throwing them out here for the hell.
Higher res pics: http://www.flickr.com/photos/beerorkid/sets/72157607200160470/
If I pull the board out how can I test the transistors to see which one is bad with a DMM? If you could assist me how to go about finding that information it would be extremely helpful. I am not too DMM or reading schematics savy. Could it be the little diodes (once hope my terminology is correct) on the lamp sockets themselves?
I am ready to start doing this work myself and hope you can give me a few ideas.
Got a baby pacman a bit ago and am working on getting all the lights on the playfield working. I replaced a lot of bulbs and have found an issue with two lights that are wired together that remain on at all times.
From reading over the pinrepair page on BPM it seems I must have a bad transistor (think that is the right terminology)
The AS-2518-107 lamp/solenoid driver board often has problems. Most often the 2N5060 SCRs fail causing non-working or locked-on pinball playfield lamps. The 4514 lamp decoders (U1,U2) usually don't fail though. So if some playfield lamps don't work (and its not the bulb or lamp socket), suspect a 2N5060 SCR on the lamp/solenoid driver board connector. Note the color of the wire going to the problem lamp socket. Then find this wire color on the lamp/solenoid driver board connector. Then trace the connector its corresponding 2N5060 SCR. The lower leg of the SCR can be grounded, and the playfield light should turn on. If it does the wiring from the SCR to the playfield lamp is good, and the 2N5060 SCR should be replaced.
Also the SE9302 transistors (TIP102 replaceable) and CA3081 pre-driver (U3,U5) chips can fail causing locked-on or non-working solenoids. The solenoid drivers are decoded by a 74LS138 chip at U4. Also on this board is the +5 volt voltage regulator at Q41 and a 11,000 mfd filter capacitor at C2. This supplies power to the -133 MPU board. Often the C2 filter capacitor needs to be replaced.
I am thinking it must be a 2N5060 that is causing the problem on the lamp/solenoid driver board causing the issue.
I looked over the manual. Link (hosting it myself for faster DL) and it does not seem as informational as the ones for my other pinballs. I cant seem to figure out which transistor it might be that corresponds to the lights messed up.
The 2 and the A I am pointing at in the 2nd row are the ones that stay turned on constantly.
bottom view
Lamp board. (can get better pic if needed. Pretty much just throwing them out here for the hell.
Higher res pics: http://www.flickr.com/photos/beerorkid/sets/72157607200160470/
If I pull the board out how can I test the transistors to see which one is bad with a DMM? If you could assist me how to go about finding that information it would be extremely helpful. I am not too DMM or reading schematics savy. Could it be the little diodes (once hope my terminology is correct) on the lamp sockets themselves?
I am ready to start doing this work myself and hope you can give me a few ideas.
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