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Medieval Madness Flippers not working

W

wbk

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Joined
Dec 27, 2020
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71
Location
Aargau
Hi
On my Medieval Madness the flippers have stopped working. I've checked the fuses F115, F116, F117, F118 all are fine.
The power for the flipper coils seems to be all right: J119: pin 1,2 RED-GREEN have 70V, 4,5 RED-BLUE have 70V als well
Switch edges test the flipper opto board switches work very well, L, U.L, R, U.L Flipper buttons
Flipper Coil Test 12.01-04 Repeat/running (cycling through 01-04) nothing happens
Checked as well that the ribbon Cablefrom CPUJ211 to Power Driver Board J102 is inserted correctly

Any help is very appreciated
Thank you
 
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Run switch test and see whether the door interlock switches are working
 
Flippers are optos - in switch test press flipper button- what does it show?

edit.. sorry just re- read the post..
 
There are TWO switches on your door - one is electronic and goes to the CPU - the other cuts off the 70v and 20v supplies to the playfield. It has 4 heavy wires on it. You can trace it back and find where it attaches (by the transformer) and bypass it.
 
Dave Bishop said:
The coin door - mine has 2 switches switch 22 is the bottom of the two. The top switch cuts the power to the flippers
View attachment 138329
Click to expand...
Hi David
Many thanks for this video
So If I understand your video correct: With open coin door, pressing this second switch (NOT the 22) enables the flippers. correct?
Does not on my PIN in that case something is wrong with that switch.
 
Yes that’s correct.
Check the switch and the wires to where they go. That’s about as technical as
I get. @Pick Holder or several other chaps on here know their stuff and can maybe chime in here.
 
Dave Bishop said:
Yes that’s correct.
Check the switch and the wires to where they go. That’s about as technical as
I get. @Pick Holder or several other chaps on here know their stuff and can maybe chime in here.
Click to expand...
Hi Dave
Perfect thank you, at least I know where to search. Next I have to google how to test a cherry switch, then follow the cables, thanks for your help!
 
CHRIS B PINBALLS said:
Do all the other coils work ?
Click to expand...
All except the flippers and the trolls. The flippers and the trolls are wired J119 which have the 70V. The coin door interlock switch assembly (part no. A-18249-3), the cherry switch works as well, I've mesured it open (no connections between the according pins) and pressed or pulled out and the according pins have a connection.
 
Ok so all the big coils then so it’s definitely not the interlock switch on the coin door and very doubtful the flipper button opto s if the trolls don’t work either
Did you say you had 70v on all the lugs on the flipper coils and troll coils ?
 
It may be worth with the game off giving the asic chip on the cpu a push home and just turn the small ribbon the other way round
 
CHRIS B PINBALLS said:
Ok so all the big coils then so it’s definitely not the interlock switch on the coin door and very doubtful the flipper button opto s if the trolls don’t work either
Did you say you had 70v on all the lugs on the flipper coils and troll coils ?
Click to expand...
Yes I've got 70V on all the lugs on the flipper coils and troll coils
 
Ok is j120 connected if so you could check you have 70v on the wires there I think you probably will if so then you have a fault on the driver board or a data problem did you push the asic home and swap the ribbon cable round between the cpu and driver board
The next step would be to ground the transitor for the coils quickly and see if you get a flip
 
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Have you removed the fuses and tested them with a multimeter one at a time?

Check F108 as well.

Check connector J119, J120 are correctly plugged in.

It is also worth in the switch test checking the flipper buttons too (this will make sure you have 12v to optos).
 
CHRIS B PINBALLS said:
It may be worth with the game off giving the asic chip on the cpu a push home and just turn the small ribbon the other way round
Click to expand...
Unfortunately still the same
Pick Holder said:
Have you removed the fuses and tested them with a multimeter one at a time?

Check F108 as well.

Check connector J119, J120 are correctly plugged in.

It is also worth in the switch test checking the flipper buttons too (this will make sure you have 12v to optos).
Click to expand...
Hi Chris
Thank you for your hints
I've checked now all the fuses including F108 as well all fine, J119, J120 are correctly plugged in
>It is also worth in the switch test checking the flipper buttons too
They work
 
CHRIS B PINBALLS said:
The next step would be to ground the transitor for the coils quickly and see if you get a flip
Click to expand...
Hi Chris
Many thanks, I've grounded the Diode 89 of Transistor 87 (Q87), and the left lower flipper worked. so it must be the control of the transistor 87, would you agree? In my oppinion the Power driver board J02 to CPU board J211 data bus connection must be working, as the flashers work.
Could it be that U8 / 74LS374 is faulty?
 
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Did you push the asic like I said it’s worth just swapping round the ribbon it only take one date line to be broken and that could be your issue even if the flashers work
I haven’t looked at schematic but if you have exhausted everything else it does look like the latch chip that controls the flipper s and trolls
 
CHRIS B PINBALLS said:
Did you push the asic like I said it’s worth just swapping round the ribbon it only take one date line to be broken and that could be your issue even if the flashers work
I haven’t looked at schematic but if you have exhausted everything else it does look like the latch chip that controls the flipper s and trolls
Click to expand...
Hi Chris, yes I've pushed the asic and I've mesaured every connection on the ribbon cabel with the multi meter, they all work. So I assume the ribbon cable is fine, or could it be that I miss something?
 
As the Flippers and Trolls are driven by J120 and grounding driver tab on the power board makes the coil fire that suggests that the the connections are correct. As everything else appears to be working then the common component would be the LS374 so I would look at that.

Do you have a scope or logic probe?

How are your soldering skills?

David
 
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DAFlippers said:
As the Flippers and Trolls are driven by J120 and grounding driver tab on the power board makes the coil fire that suggests that the the connections are correct. As everything else appears to be working then the common component would be the LS374 so I would look at that.

Do you have a scope or logic probe?

How are your soldering skills?

David
Click to expand...
Hi David
Many thanks, I've just ordered a logic probe. And for the test then would you suggest to test that the according data lines D0-D7 have a signal as well as the OC (1) and CLK(11)
Soldering skills: Learning. My friend is an electrical engineer with a lot of experience, he will support me.
 
Check the clock first as the OC and data lines are used elsewhere. It should latch on falling edge of clock.

David
 
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