(Topic ID: 40746)
Coeur D'alene, ID
Those wire-wound cement resistors in the lamp matrix circuit get quite hot under normal conditions. Are there more efficient alternatives that don't put out as much heat?
Do nothing. Those run hot normally, and ALL boards are discolored underneath them.
Quoted from Crash:Those wire-wound cement resistors in the lamp matrix circuit get quite hot under normal conditions. Are there more efficient alternatives that don't put out as much heat?
Replacing the tip102s/107s with MOSFET equivalents, and then ripping out those resistors entirely. Not a simple mod, but not super difficult. I've never bothered on a machine in home use. If I was routing one, I'd probably bother with it.
Quoted from Ronnie1114:.Did you see how burnt they are? I cant see that as being normal
If you think that's toasty, you haven't seen toasty! 
Perfectly normal, perfectly fine. Don't touch them puppies when the game is on.
Quoted from TheKorn:Do nothing. Those run hot normally, and ALL boards are discolored underneath them.
Replacing the tip102s/107s with MOSFET equivalents, and then ripping out those resistors entirely. Not a simple mod, but not super difficult. I've never bothered on a machine in home use. If I was routing one, I'd probably bother with it.
Interesting. Never heard of doing that one before. Just jumper the traces where you remove the resistors, I take it?
Quoted from Frax:Remind me to send you a picture of my Shuttle's power board...that's nothing. It's burned to fiberglass, just from the GI!
Nice! Gotta love the GI from that era. The GI connector in my old Black Knight got so hot it actually desoldered itself from the board at one point. Decided it was time to rebuild that connector finally at that point...LOL! I miss that game...
Quoted from Frax:Remind me to send you a picture of my Shuttle's power board...that's nothing. It's burned to fiberglass, just from the GI!
Post it here!
I have some boards that went super nova from those resistors i can take pics of if i remember to do so.
Looks like they where already replaced at one point which is a good thing. I would just keep an eye on it every once in a while. Likely nothing to worry about.
Pretty typical. I replace the TIP42s with MOSFETS and use a zero ohm jumper in place of the resistor.
Looks nice and neat, and will never burn again.
Sana'a
Thanks everyone, I was having problems with the solenoids and not knowing much figured it was that. Now that I know that those 2 problems are completely unrelated I will keep looking.
Quoted from vid1900:Hey, let's not forget, that's Williams quality!
WMS: Wires May Sizzle.
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