BK2K Hold winding issue

I've been having an on going problem with my bk2k where the right flipper has been getting hot shortly after playing a game. After a full rebuild, new EOS and everything else the issue still remains. I did notice something later on and I assume it relates. If I slip a piece of plastic between the eos of the left flipper the left flipper albeit slowly raises and holds it's self in the flipped position. Doing this to the right side and I only get the slightest twitch out of the flipper. What I find odd is in game the flipper flips and holds without issue until it gets stupid hot of course. All coils are new and all diodes on the flipper are correct so that doesn't seem to be an issue. What would cause the hold or weaker winding to just not work like this. Am I missing something? On all my other games with plastic between the normally closed eos the flippers on both sides seem to still use the hold winding to slowly rasie the flipper. Thanks for any help.

#2 5 years ago

DEC

GRUMPY

Pinside member

The hold winding isn't very powerful, sometimes it can't raise the flipper bat with out help. This maybe from drag from the bushing, misalignment of the paw, the bolt on the link or the paw bushing bolt maybe to tight. The paw maybe not centered vertically and might be dragging. Since it holds during the game it tells it's working. Remove the return spring and check for free movement of all the parts first.

#3 5 years ago

ELD

darcangeloel

Pinside member

Done also yeah you are correct with a bit of help it engages and holds. However even with the spring off everything moves nice and freely. Coil is still getting stupid hot

Quoted from GRUMPY:
The hold winding isn't very powerful, sometimes it can't raise the flipper bat with out help. This maybe from drag from the bushing, misalignment of the paw, the bolt on the link or the paw bushing bolt maybe to tight. The paw maybe not centered vertically and might be dragging. Since it holds during the game it tells it's working. Remove the return spring and check for free movement of all the parts first.

#4 5 years ago

DEC

GRUMPY

Pinside member

OP
Quoted from darcangeloel:
Coil is still getting stupid hot

This is a different issue. Take a pic of the flipper assembly both in the up position and at rest, so I can see the EOS switch clearly.

#5 5 years ago

237

slochar

Pinside member

7y 86,550 6,879

OP
Quoted from darcangeloel:
I've been having an on going problem with my bk2k where the right flipper has been getting hot shortly after playing a game. After a full rebuild, new EOS and everything else the issue still remains. I did notice something later on and I assume it relates. If I slip a piece of plastic between the eos of the left flipper the left flipper albeit slowly raises and holds it's self in the flipped position. Doing this to the right side and I only get the slightest twitch out of the flipper. What I find odd is in game the flipper flips and holds without issue until it gets stupid hot of course. All coils are new and all diodes on the flipper are correct so that doesn't seem to be an issue. What would cause the hold or weaker winding to just not work like this. Am I missing something? On all my other games with plastic between the normally closed eos the flippers on both sides seem to still use the hold winding to slowly rasie the flipper. Thanks for any help.

You isolate the EOS switch contacts and the flippers raise up on their own without you pressing in the flipper buttons? That should never be.

I'm not sure what you're trying to test by holding the flipper button in with this test anyway - you'd know right away that the hold coil wasn't working because the flipper wouldn't hold (and would reflip/chatter). Voltage is getting into the flipper when it shouldn't and causing it to heat up, although right flipper coils getting hot on BK2k aren't surprising because it's very right flipper-centric.

IIRC there was a supplier a couple years back that had their diodes installed wrong on the coils - is it possible they are wrong/backwards?

#6 4 years ago

ELD

darcangeloel

Pinside member

As requested here are pictures and a video if the flipper in action. No biding that I am seeing so no clue why the coil continues to get hot. Diodes are brand new and seem to be in the right direction.

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#7 4 years ago

ELD

darcangeloel

Pinside member

Sorry my post must have been confusing it only raises when pressing the flipper button. This is a non issue after discussing with grumpy. Something else is going on. Im hoping the pictures and video might help.

Quoted from slochar:
You isolate the EOS switch contacts and the flippers raise up on their own without you pressing in the flipper buttons? That should never be.
I'm not sure what you're trying to test by holding the flipper button in with this test anyway - you'd know right away that the hold coil wasn't working because the flipper wouldn't hold (and would reflip/chatter). Voltage is getting into the flipper when it shouldn't and causing it to heat up, although right flipper coils getting hot on BK2k aren't surprising because it's very right flipper-centric.
IIRC there was a supplier a couple years back that had their diodes installed wrong on the coils - is it possible they are wrong/backwards?

#8 4 years ago

DEC

GRUMPY

Pinside member

https://pinside.com/pinball/forum/topic/pinbot-left-flipper-blows-fuse-and-melts-lane-switch-plastic#post-3607624

Read this post from a while ago.

#9 4 years ago

ELD

darcangeloel

Pinside member

Interesting, a good read none the less. I squared up the eos and sanded the contacts a bit to get that coating off. I also had replaced the flipper button leaf switch so I did the same there as well. Perhaps it is slightly better but the coil is still getting really hot. You mentioned using acetone should I need to do that? Or should I sand more? I find it odd that this would be the issue as I've replaced them on my other games and never had this problem. Thanks!

Quoted from GRUMPY:
Read this post from a while ago.
https://pinside.com/pinball/forum/topic/pinbot-left-flipper-blows-fuse-and-melts-lane-switch-plastic#post-3607624

#10 4 years ago

DEC

GRUMPY

Pinside member

OP
Quoted from darcangeloel:
Perhaps it is slightly better but the coil is still getting really hot.

Adjust for more closing pressure. Also since the coil is new,check the coil for the correct resistance 4.7 power and 161 hold.

#11 4 years ago

ELD

darcangeloel

Pinside member