(Topic ID: 251265)

Pinbot Flipper Issue


By sixleggeddog

8 days ago



Topic Stats

  • 7 posts
  • 3 Pinsiders participating
  • Latest reply 1 day ago by sixleggeddog
  • Topic is favorited by 1 Pinsider

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#1 8 days ago

Hi all. So I bought pinbot in June (my first pin!). At the time of purchasing it, when you depressed the flipper buttons, the flippers would just flip up and down repeatedly, and the guy I bought it from said he thought a flipper rebuild would fix the issue. I also noticed that after a time the flippers would lose power altogether and he said it was probably an issue with the flipper power supply board.

Since I purchased the game, I've done a complete flipper rebuild on both flippers and also replaced the flipper power supply board. Since the flipper rebuild most of the time when I boot the game up, pinbot will play fine (flippers act normally and are powerful). The only thing thats odd is that the flippers will still flip between games when they should have no power. However, sometimes (and it has been doing this a lot more as of late) after playing for a little bit the flippers will start to randomly flip up and down, and after a short time will stop flipping altogether. Also, if you depress both flipper buttons down at the same time when it's doing this, then the flippers simultaneously flip up and down so the issue is linked to both flippers.

I'm a total novice when it comes to pinball repair, and have no background in electronics so any help is appreciated! I'm not even sure where to start honestly.

Thanks!

#2 8 days ago

Pinbot has a fairly simple flipper circuit. Power is always at the coil, rectified at the power board. The ground comes from the mpu through the flipper buttons. For it to flip when gsme is off, means tbe relay on the mpu board is either energized all the time or the contacts on the relay are fused closed. Those grounds come from 1j19 pins 1 and 2 on the mpu. Follow those traces back to the relay and see if theres anything burnt on the board. Also, any battery corrosion on this board?

#3 7 days ago
Quoted from robertmee:

Pinbot has a fairly simple flipper circuit. Power is always at the coil, rectified at the power board. The ground comes from the mpu through the flipper buttons. For it to flip when gsme is off, means tbe relay on the mpu board is either energized all the time or the contacts on the relay are fused closed. Those grounds come from 1j19 pins 1 and 2 on the mpu. Follow those traces back to the relay and see if theres anything burnt on the board. Also, any battery corrosion on this board?

Oh ok thanks! No battery corrosion on the board as far as I can tell. I will try and follow the traces and let you know how it goes.

#4 4 days ago
Quoted from robertmee:

Pinbot has a fairly simple flipper circuit. Power is always at the coil, rectified at the power board. The ground comes from the mpu through the flipper buttons. For it to flip when gsme is off, means tbe relay on the mpu board is either energized all the time or the contacts on the relay are fused closed. Those grounds come from 1j19 pins 1 and 2 on the mpu. Follow those traces back to the relay and see if theres anything burnt on the board. Also, any battery corrosion on this board?

Update: every time I boot the game on now there is no power to the flippers between games (as it should be), but the flipper power goes in and out repeatedly almost right away. The reason it is losing power is because the relay (k1) is opening and closing constantly during the game when it should obviously remain closed during the game. This is whats been making the flippers go up and down. Thanks for pointing me in the right direction to that!

I have not yet taken the board out of the machine to check and see what it looks like on the back, but I did check the transistor right before the relay (Q67) because I read that goes bad fairly often. It tested good on the multimeter, but I also ready that transistors could "test" good but still be bad, so maybe that transistor is still the issue?

I also have not tested the relay itself yet to see if thats bad (need to do some research on how to do that). But I feel like I am slightly closer to figuring out the issue even though the game is working less now, haha.

#5 4 days ago

A logic probe is your friend here....you can probe the base of the transistor and see if it is being told to pulse which would indicate a problem further up stream.

#6 4 days ago

The solder joints on the relay to the board could be cracked, or it could be the driver transistor. Get the board out and inspect the connection the relay is a relatively heavy component and it is prone to having cracked joints.

#7 1 day ago
Quoted from slochar:

The solder joints on the relay to the board could be cracked, or it could be the driver transistor. Get the board out and inspect the connection the relay is a relatively heavy component and it is prone to having cracked joints.

Quoted from robertmee:

A logic probe is your friend here....you can probe the base of the transistor and see if it is being told to pulse which would indicate a problem further up stream.

Thanks for the suggestions guys! When I have some time I'm going to pull the board off and see what it looks like on the back/check those solder joints. I also might just replace that transistor and see if it fixes the issue, since I need to order another transistor to fix one of the pop bumpers anyways. Seems like an inexpensive way to check out that problem.

If that doesn't work I'll buy a logic probe/figure out how to use it and check the transistor as robertmee suggested.

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