Arcade Collecting > Restorations & repair
Star Wars - fully working!
Spyridon:
--- Quote from: Level42 on April 06, 2009, 06:18:03 am ---Of course you can test them on the connectors on the deflection board too.
--- End quote ---
Good point. That should make things easier.
Spyridon:
I've been reading up on transistors so that I can learn some more about what I'm doing. According to what I've read, there should be three parts: the base, collector, and emitter. Looking at the picture below, I have 5 pins? I was expecting only three. How do I tell what is what? The two without wires are different than the other three, so I can probably assume the three with wires are the 3 elements.
Bear with me on what may seem like dumb questions, but I'm treating this as a learning experience.
Level42:
Not a dumb question. Those transistor holders are pretty weird things.
Every transistor has three cpnnections only. What you see (yellow arrow) is where the pin of the transistor is inserted into the holder. That metal holder is connected to the solder "eye" of that holder (pointed by the green arrow). Try to measure between them in diode test and you will hear a beep (and 0 reading) as they are directly connected.
Now, I already hear you say, where is the third pin ?
The third pin is not there. The metal case of the transistor is the third connection. This is why the third solder-eye is connected to the screw.
Spyridon:
Okay, I think that makes sense. Thanks!
Kevin Mullins:
Typically if it didn't blow a fuse those transistors are most likely still good. (should still check them though) Not only look for dead shorts, but also if one is comeletely OPEN then it's bad as well.
Absolutley can not stress enough to check every pin for bad solder joints.
Especially the header pins for the connectors that lead to those larger chassis mounted transistors..
If you find ANY bad solder joints around those header pins, check the small resistors and transistors in that general area.
Spot killer LED being on indicates you are missing at least one of the axis. (X or Y)
Which in turn shuts the beam completely off in order not to burn the screen.
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