Data East Star Wars (Data East, 1992) flippers problem

[autocthon]

Have a data east starwars. It started out with one mal-functioning flipper and quickly grew to blowing both flipper fuses. This happens only when the start game button is pressed. This also happens only if the coils are in the circuit. Checked the coils but replaced them anyway just to be sure. replaced the pc board but no help. I have the manual but the schematics are hard for me to understand for some reason. I've read and used a lot of schematics but these don't seem to conform to what I've always used. The grid system to follow from page to page is not there or I'm just mis-reading them. I confess it's kicking my behind--any help?

 

[Coil_Smoke]

Do the diodes at flipper coils test ok? I see 4 fuses on your flipper board. What F# fuse is blowing? You say"This happens only when the start game button is pressed" Does this mean the fuse blows before a flipper button is pressed?

 

[pinballdaveh]

yes i think the manual is cut short too. i found the full schematic and info in the data east batman manual for the flipper PCB.

 

[autocthon]

Do the diodes at flipper coils test ok? I see 4 fuses on your flipper board. What F# fuse is blowing? You say"This happens only when the start game button is pressed" Does this mean the fuse blows before a flipper button is pressed?

All the diodes I checked (the ones on the coils) checked OK but replaced one of them anyway just for the hell of it. And you're right, just hitting the flashing start button blows a fuse. There is a dead short somewhere, it's not flaky or dim or intermittent, just a dead short and because I am too stupid to figure out how to read the path from one page to the next I can't follow component flow. disconnecting both coils--no blow, re-connecting either one, blows corresponding fuse. Gonna turn in my fluke and get a BFH.

 

[pinballdaveh]

here are some things to check with your fluke. un-plug machine and remove flipper fuses F1 and F3. check resistance in both polarity directions of both the flipper coils.there should not be any shorts, and readings should be the same for both coils. next check resistance of CN2 pin 8 or 9 to each of the flipper transistor output fuse clips for each flipper(it is prob. the clip NOT next to the connector) no shorts should be found. disconnect meter. plug in machine and turn on to attract mode, do not press reset button yet. test for dc volts from CN1 pin 6 or 7 ground to each of the fuse clips you were just at. constant 50vdc is NOT correct, it should be a pulsed/timed 50vdc signal when flipper button is pushed and a 8vdc used for the coil hold in.. press reset button and do voltage tests again. the flipper board is also part of the switch matrix, so the flipper buttons can be used for other functions example entering initials or special game play functions. please post your readings and go from there.

 

[Coil_Smoke]

We're All Morons Compared To Somebody ...

Hey "autocthon" , Don't be so hard on your self. Those flipping schematics are a challenge for everyone. I almost gave up just finding the diagram of your flipper board.
http://www.ipdb.org/machine.cgi?id=2358
http://mirror2.ipdb.org/files/2358/Data_East_1992_Star_Wars_Schematic_Diagrams_English_Manual_pages_46_69.pdf
If fuse F5 is blowing check bridge rectifier module. It's kinda weird the problem stopping when you disconnect the coils. One coil? Both coils? Why is all that current flowing while no flipper is energized? Do the flippers move before the fuse gives up ? Are you sure you have the right size fuse? Would it be safe to try few amps more(maybe not a good idea). You said this problem came on slow and got worse. Sounds like a capacitor going bad. And yeah... What voltage and type of signal/wave form is making it's way to the flipper coils. I guess it is supposed to be 50 volts of ripple free filtered DC when the flipper is activated. Do both circuits read the same?

 

[autocthon]

Hey "autocthon" , Don't be so hard on your self. Those flipping schematics are a challenge for everyone. I almost gave up just finding the diagram of your flipper board.
http://www.ipdb.org/machine.cgi?id=2358
http://mirror2.ipdb.org/files/2358/...matic_Diagrams_English_Manual_pages_46_69.pdf
If fuse F5 is blowing check bridge rectifier module. It's kinda weird the problem stopping when you disconnect the coils. One coil? Both coils? Why is all that current flowing while no flipper is energized? Do the flippers move before the fuse gives up ? Are you sure you have the right size fuse? Would it be safe to try few amps more(maybe not a good idea). You said this problem came on slow and got worse. Sounds like a capacitor going bad. And yeah... What voltage and type of signal/wave form is making it's way to the flipper coils. I guess it is supposed to be 50 volts of ripple free filtered DC when the flipper is activated. Do both circuits read the same?

Guys: I'm leaving the quotes in for continuity's sake. Thanks to all with the help and I will keep this up but I just wanted to let you know that this is a weird trouble-shooting scenario. It's my son-in-laws machine that I am trying to fix from 600 miles away. I showed him how to use the cheap DVM he bought and now I have to have him relay all to me and so on and so forth. So, if I am slow in responding please don't hold it against me. I used to work on these things when they were all relays back in the cretaceous. I did pull the cpu board while there and the "blanking" section looked bad. Swollen cap and a lot of overheated and corroded soldier joints (and no, the 3 batteries hadn't leaked enough to do this) don't think think this had anything to do with the flippers but after 30 years in electronics not much surprises me anymore. I feel like I need my logic probe and a scope for this thing.

 

[pinballdaveh]

have you explained to your son how to read junctions with his DMM?