A marginal end-of-stroke switch could be not-fully-closed and periodically opening up, triggering the power coil to come back on (as per design - well, at least until the game starts noticing that it's broken and starts ignoring it)If the coil is getting hot then it’s obviously staying energised, which rules out a mechanical problem. A stuck flipper would presumably be on low power anyway if just mechanically stuck anyway, and should not get hot no matter how long it’s held like that (otherwise cradling would be dangerous)
It is certainly feasible that electrical problems manifest when components elsewhere in the machine have warmed up.
I agree with the above, get some extra wire and hook it up so you swap the flippers over electronically - ive done this twice and helped tell me where the fault is. I had a very weird one on my LOTR which turned out to be a dodgy transistor that became unreliable when it heated up, from cold it worked perfectly. Swapped the transistor and problem was solved.Fair, fair, I get that totally.
It's just that you're at the point where further testing gets invasive. Now I think about it, a more sensible suggestion for completely eliminating electronics versus physical issues, is instead of swapping the flipper assemblies - just swap the wires over. Making sure to swap the wires for the coil and the EOS switches, of course.
Have fun playing the game like that until the problem resurfaces... and if it's now the left flipper, forget about anything on the playfield, it's up in the backbox. And it's going to be one of the transistors... almost certainly.
Test the flipper coils in test mode (remember 2 drivers per coil, power and hold), then test the flipper optos in the switch test. Look specifically for optos going on and off very fast. My guess - optos failing/breaking down after being on for a period of time...when it’s stuck, if I power off it drops straight away - surely wouldn’t if it’s a mechanical issue?
Also why would the coil get hot if it’s just stuck mechanically, no power going to it without flipper button pressed surely?
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Coils test fine - until the fault occurs, then the issue repeats itself in test mode too (will stay up on power AND hold test).Test the flipper coils in test mode (remember 2 drivers per coil, power and hold), then test the flipper optos in the switch test. Look specifically for optos going on and off very fast. My guess - optos failing/breaking down after being on for a period of time
Yep can’t argue with that - doneWould be nice to change the thread title to something more meaningful. There's a lot of good info here that might help future visitors, but they'd struggle to find it if the thread is just "Help please"
and when you switch off after this happens, the flipper immediately drops down to rest position?Coils test fine - until the fault occurs, then the issue repeats itself in test mode too (will stay up on power AND hold test).
Opto test fine, and issue stayed on same flipper after switching flipper optos round.
I haven’t yet gone straight into an Opto test directly after fault occurs - I’ll try that, I did start hammering the flipper buttons last time it stuck but that didn’t do anything.
Again cheers for all the help, any suggestions are welcome, frustrating but I do enjoy the learning curve.
He said he swapped the flipper optos around and the issue stayed with the same flipper.and when you switch off after this happens, the flipper immediately drops down to rest position?
Do you have another cpu and driver board to swap over and try ? If you want to send me them it i could try them in my gofers
I’d start by swapping the cpu first as it still sounds like a switch side issue
I’m talking about lm339s on the switch circuit when I say ‘switch side’ not optos and they are on the cpu board for wpc-95He said he swapped the flipper optos around and the issue stayed with the same flipper.
The fact that it's a warm-up related issue makes me doubt it's a transistor on the switch side (on the CPU board) - well, an IC or diode anyway, no discrete transistors in that pathway IIRC - the drive-side of things deals with a lot more power and is what I think is the bigger bet for having failed; either one of the transistors of the Darlington pair though it's almost always the main drive (not the pre-drive.)
Nobody's ignoring you fella - in honesty I agree with you about the opto comparators being more likely than a partial transistor failure. Though transistor failure in this way is not impossible - AlanJ above has said he's had a case just like this. The coil getting hot made me think it wasn't a 'stuck switch' as it wouldn't get hot too quickly if it was stuck on with just the hold winding - and swapping the opto boards ruled out a strobing flipper opto signal for me.I’m talking about lm339s on the switch circuit when I say ‘switch side’ not optos and they are on the cpu board for wpc-95
Transistors normally fail completely either open or dead short, whereas comparators can leak get stuck after being on for awhile
anyway feel free to ignore me and my advice... I’m just trying to guess at the most likely outcome to help the op out. It’s easily solved if I had the boards here
Hopefully not purely because it's an easier soldering job to replace a transistor than a DIP14 IC - unless there's already been a replacement and someone added a socket!My money is on Jim being right
I'm going to cry if it turned out just to be a dirty connectorGood news and bad news.
Other than unplug J120 and J119 to test the diodes (this was my way of taking them ‘out of circuit’ that in fact didn’t make any difference) I haven’t done anything too invasive but....
The issue seems to have stopped, been playing the **** out of it, using both flippers a lot and can’t seem to replicate the fault!
Good news but also frustrating as it may return, to be continued...... maybe