Disco Fever
Williams, 1978New to me machine. Obvious burns to both coils listed above. Pulled the driver board and also has 2 burnt resistors. Thinking of doing vids mod that removes them totally, replacing them with jumpers and then replacing the TIPs with Mosfets.
Am I on the right track ? Thanks!
I think what you're describing with replacing the resistors with jumpers and replacing the TIPs with Mosfets is a modification for the lamp circuit, and is unrelated to your coils locking on. I would do that modification, then also replace the driver and pre-driver associated with the two coils you're having problems with. You're looking at Q1 and Q2 for the ball release, and Q40 and Q41 for the knocker. After you've done that, check the resistance of the coils, and replace the sleeves. If you can't get the sleeves out because of the heat damage I'd replace them.
Quoted from Knxwledge:I think what you're describing with replacing the resistors with jumpers and replacing the TIPs with Mosfets is a modification for the lamp circuit, and is unrelated to your coils locking on. I would do that modification, then also replace the driver and pre-driver associated with the two coils you're having problems with. You're looking at Q1 and Q2 for the ball release, and Q40 and Q41 for the knocker. After you've done that, check the resistance of the coils, and replace the sleeves. If you can't get the sleeves out because of the heat damage I'd replace them.
Right you are! There is obvious burning in that area as well. I'm not comfortable with enough with soldering in that area though. Time to send the boards out.
IMG_20220530_100527 (resized).jpgIMG_20220530_100535 (resized).jpgI posted the incorrect transistors for the ball release, it would actually be Q14 and Q15, Q1 and Q2 are part of the special solenoid driver circuit. That transistor you posted a pic of is Q17, so I would also check coil 2, "FEV" Drop Target Reset
Quoted from Knxwledge:I posted the incorrect transistors for the ball release, it would actually be Q14 and Q15, Q1 and Q2 are part of the special solenoid driver circuit. That transistor you posted a pic of is Q17, so I would also check coil 2, "FEV" Drop Target Reset
Looks like it has been replaced at one point. Poorly I might add. Probably the wrong coil.
Quoted from AZDbacker:Looks like it has been replaced at one point. Poorly I might add. Probably the wrong coil.
http://pinball.flippers.info/discofeverinstructions.pdf
PDF page 27 has the coils
https://www.pinwiki.com/wiki/images/d/dc/System3-7DriverBoardLayout.jpg
Driver board layout
Quoted from Knxwledge:http://pinball.flippers.info/discofeverinstructions.pdf
PDF page 27 has the coils
https://www.pinwiki.com/wiki/images/d/dc/System3-7DriverBoardLayout.jpg
Driver board layout
SWEEEEET! Thanks!!
Quoted from Knxwledge:Heh I just emailed Chris Hibler asking him to repair a board of mine and he says his backlog is too big. Clive at Coin Op Cauldron is great, he did great work on a System 80 Gottlieb sound board I sent him
Kris at Firebird Pinball got it squared away for me. He's fantastic.
Update on post board repairs: IT'S ALIVE! Swapped out the 3 suspect coils. First fire up and it goes into attract mode. I add a credit, press start and nothing. Anyone have the default dip switch settings handy?
System 3 wms games are all in the manual for settings. Ipdb should have it for df. It sucks setting options on these because of the arcane way you have to do each one.
If you can burn roms the beginning of the game ROM has the factory restore defaults you can hex edit them to your liking... Makes it easier.
Quoted from slochar:System 3 wms games are all in the manual for settings. Ipdb should have it for df. It sucks setting options on these because of the arcane way you have to do each one.
If you can burn roms the beginning of the game ROM has the factory restore defaults you can hex edit them to your liking... Makes it easier.
I have the manual. Can't say I am understanding it though nor can I burn roms.
I have done some initial troubleshooting and here is where I am at:
* All switches register and score EXCEPT the slingshots.
* No coils fire except the pop bumpers and flippers.... which work perfectly
* All fuses have been checked and verified good via multimeter
What's next?
Quoted from AZDbacker:I have the manual. Can't say I am understanding it though nor can I burn roms.
You have to set the dip entry banks and hit enter on the mpu board. I'd vote it as the worst settings setup in pinball ever.
"The driver board driver transistors are the most probable source of solenoid problems. But an easy first test is to measure the voltage at connector 3J3 pins 6-9 on the power supply board, which should show about 28 volts DC. If there is no voltage, check the solenoid fuse F2. If there is a lower voltage, the backbox mounted bridge rectifier has probably partially failed. If the voltage is higher than 28 volts, don't worry about it (as long as it's not more than 47 volts!) The "unloaded" system should measure higher than the "loaded" 28 volts DC."
I'm not getting anything on those pins with my MM. Ordered a rectifier as well....
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Mesa, AZ
