(Topic ID: 78330)

CFTBL flipper coils overheating


By rygar

5 years ago



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  • 76 posts
  • 21 Pinsiders participating
  • Latest reply 5 years ago by Atomicboy
  • Topic is favorited by 8 Pinsiders

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There are 76 posts in this topic. You are on page 1 of 2.
#1 5 years ago

Both flipper coils are overheating in my CFTBL. I have done the following things:

- replaced both coils with brand new ones,
- swapped fliptronic board with working fliptronic board from my Roadshow,
- swapped flipper opto boards with working ones from my White Water,
- replaced both EOS switches (also tested the game without EOS switches),
- replaced transformer.

The coils are still overheating and they get too hot to touch after 15 or 20 minutes of play.

Any ideas what other things should I try?

#2 5 years ago

Check your EOS switches, 1) make sure they're set properly, 2) check for any solder splash between the conections of them. If they are getting that hot, #2 usually leaves a burn spot on the insulator between the conections where the solder is.

#3 5 years ago

Even though you swapped opto boards, clean them.

Plungers move freely in coil ?

A tiny bit of up and down play on the flipper so the pawl isn't binding on the bushing below the playfield ?

LTG : )

#4 5 years ago

Thank you for the fast reply. I have checked them out and found no solder splashes. I have taken a picture of the right one mounted and the left one removed. Is there something suspicious in those two pics?

20140124_235554.jpg 20140124_235653.jpg
#5 5 years ago
Quoted from LTG:

Even though you swapped opto boards, clean them.
Plungers move freely in coil ?
A tiny bit of up and down play on the flipper so the pawl isn't binding on the bushing below the playfield ?
LTG : )

Thanks, I will clean the opto boards. Plungers move freely. Up and down play is there, I have used the flipper alignment tool.
So if I just disconnect the EOS switches temporarily the coils should not overheat because of that?

#6 5 years ago
Quoted from rygar:

So if I just disconnect the EOS switches temporarily the coils should not overheat because of that?

The game will ignore them if you disconnect them. Forget them.

Your problem lies elsewhere.

LTG : )

#7 5 years ago
Quoted from LTG:

The game will ignore them if you disconnect them. Forget them.
Your problem lies elsewhere.
LTG : )

Thank you, I have cleaned the optos and now I am off to play a test game. I will report back.

#8 5 years ago

Good call LTG, mis-diagnoses on my part.

#9 5 years ago

I have played for about 20 minutes and the problem is still persistent. I have forgot to mention before that I have also tried two other sets of (untested) flipper optos.

#10 5 years ago

Out of desperation I have put in my RD power driver board in CFTBL, but it had no effect on coils. Are there any other (logical) things that I could try?

#11 5 years ago

this is strange problem. im still learning about this stuff, but since i been messing with flippers abit and reading abit well here is why coils can overheat.
basically a coil has a high power side, that gives the "power" to the coil, but also has a lower power side. now on non fliptronics games the end of stroke is really important, cause it will be there to put on the lower power. like i had a problem of a weak flipper on the left on a party zone, so i just adjusted the end of stroke to come on almost at the end and it solved the issue.
on creature u have fliptronics board, so even if u cut out the end of stroke switches the coil wont stay up cause the low power side wont kick on and the board would make it cut out after like a few seconds.

but anyways right from the master himself clay. hopefully he wont mind me posting this, but hey full credit to him.

On WPC fliptronics and later games, if there is a marginal flipper switch reading, this causes the high powered side of the flipper to rapidly oscillate between on and off. The holding side of the flipper coil never engages. This problem will cause the flipper coil to get very hot in a short time. First try cleaning the flipper board optics. If this doesn't work, the LM339's on the Fliptronics board at U4 and/or U6 (or CPU board on WPC-95 at U25 and/or U26) will need to be replaced.
or
Bad regulation of the 12 volt power to the optos can cause the flipper coils to get hot too. Though rare, the 7812 voltage regulator on the power driver board could be failing, or the electrolytic filter capacitor for the 12 volts.

#12 5 years ago
Quoted from marcocapetown:

this is strange problem. im still learning about this stuff, but since i been messing with flippers abit and reading abit well here is why coils can overheat.
basically a coil has a high power side, that gives the "power" to the coil, but also has a lower power side. now on non fliptronics games the end of stroke is really important, cause it will be there to put on the lower power. like i had a problem of a weak flipper on the left on a Party Zone, so i just adjusted the end of stroke to come on almost at the end and it solved the issue.
on creature u have fliptronics board, so even if u cut out the end of stroke switches the coil wont stay up cause the low power side wont kick on and the board would make it cut out after like a few seconds.
but anyways right from the master himself clay. hopefully he wont mind me posting this, but hey full credit to him.
On WPC fliptronics and later games, if there is a marginal flipper switch reading, this causes the high powered side of the flipper to rapidly oscillate between on and off. The holding side of the flipper coil never engages. This problem will cause the flipper coil to get very hot in a short time. First try cleaning the flipper board optics. If this doesn't work, the LM339's on the Fliptronics board at U4 and/or U6 (or CPU board on WPC-95 at U25 and/or U26) will need to be replaced.
or
Bad regulation of the 12 volt power to the optos can cause the flipper coils to get hot too. Though rare, the 7812 voltage regulator on the power driver board could be failing, or the electrolytic filter capacitor for the 12 volts.

Hello.

Thank you for the 12V regulation idea. I had a similar problem on my IJ and +12 V was the problem there. I have tried to swap the CFTBL driver board with a proved working one from my RS, but that unfortunately did not help.

#13 5 years ago

Just for the kicks of it I have put a spare CPU board in it, but no luck. I will try with third pair of coils.

1 week later
#14 5 years ago

Tried third pair of (new) coils with no luck. In the meantime I have installed a C2 cap on the fliptronic board and also replaced the ribbon cable, also with no luck.
Any ideas? This problem is driving me crazier.

#15 5 years ago

Measured voltage on coils before and after overheating - it has a constant value of 75V on both coils.

#16 5 years ago

hi rygar,i looked a your pic of the coil still mounted.do you have 1 thin wire left lug, 1 thick wire mid.lug ,..1 thick and 1 thin wire right lug.in the pic I see only 1 thick wire on the right lug.also are those wires rubbing against the diode leads? I'm looking at your first pic. g.l.joe

#17 5 years ago

Hi, Joe. Thank you for your suggestion. I will check the coil later today.

#18 5 years ago

The temperature of the coils could be subjective. Just how hot do they get? Hot enough to melt plastic?

Maybe there is no fault at all?

#19 5 years ago
Quoted from Homepin:

The temperature of the coils could be subjective. Just how hot do they get? Hot enough to melt plastic?
Maybe there is no fault at all?

Thank you for your answer.
They get so hot after playing a game for 15 minutes that you cannot hold them longer than one second. The flippers also get weaker a bit by that time. I did not play the game (yet) long enough to see if they would start to melt the plasic. The coils on my RS do not get hot at all after playing the game for one hour.
I will try to measure the temperature to get the precise values on both games.

#20 5 years ago

Just a shot in the dark, but have you measured the voltage at the coils? You may be pumping more than the 50 volts.

#21 5 years ago
Quoted from silverball0:

Just a shot in the dark, but have you measured the voltage at the coils? You may be pumping more than the 50 volts.

I have measured the voltage and it was 75V. I have also measured voltage on my RS and it has the same value.

#22 5 years ago

You mentioned that you replaced the flipper opto boards; did you replace the entire assembly (board plus interruptor) or just the board? What color plastic are the interrupters? In some odd cases the (white) plastic is not entirely opaque which can cause enough light leakage to partially trigger the opto.

#23 5 years ago
Quoted from jadziedzic:

You mentioned that you replaced the flipper opto boards; did you replace the entire assembly (board plus interruptor) or just the board? What color plastic are the interrupters? In some odd cases the (white) plastic is not entirely opaque which can cause enough light leakage to partially trigger the opto.

Thank you for the suggestion. I did replace the entire assembly (actually tried 3 pairs of them). The assemblies were all old style with black plastic interruptors.

#24 5 years ago

how are the switches in test mode?
maybe you have some AC leakage across the circuits, giving you momentary open circuits?

set your DMM to AC, and check the critical DC circuits.

one other question, do the coils get hot with zero play after 10 minutes, or only with game play?

If the coils are fine without play, I would focus on binding.

#25 5 years ago

hi rygar,did you look at the coils?

#26 5 years ago
Quoted from scott_freeman:

how are the switches in test mode?
maybe you have some AC leakage across the circuits, giving you momentary open circuits?
set your DMM to AC, and check the critical DC circuits.
one other question, do the coils get hot with zero play after 10 minutes, or only with game play?
If the coils are fine without play, I would focus on binding.

Thank you for the suggestion. The coils are fine without play. They only overheat with gameplay. By binding - you mean binding between plunger and coil sleeve?

#27 5 years ago
Quoted from joe2012:

hi rygar,did you look at the coils?

Hello.

I will have a bit of time today so I plan to look at them later today. I will also measure the coils temperature.

#28 5 years ago

hi rygar, also check manual to see if they are the right coils.check resistance of both coils. g.l.joe

#29 5 years ago
Quoted from joe2012:

hi rygar, also check manual to see if they are the right coils.check resistance of both coils. g.l.joe

He has in new coils, old ones did the same thing.

Something has to keep power going to the coil even when not flipped up. Only way to over heat.

LTG : )

#30 5 years ago

I'd agree with the others to look at the flipper opto boards, but if you'd tried 3 sets (all of them with clean optos correct?), you can pretty well eliminate that as the issue. The next place would be to look at board issues, but you've eliminated board problems by swapping in good known working boards. If you've indeed already replaced the CPU, Driver board, flippertronics board, flipper opto boards, and even the transformer with known good working ones (plus new coils, EOS switches), you've eliminated all of them as the issue. That only leaves me to think you've got a wiring problem somewhere.

You might try swapping ribbon cables to eliminate those as an issue since they carry the data for the logic. Bad ribbon cables can cause all sorts of weird problems.

#31 5 years ago

I'd pull out some WPC flipper coil schematics and check the wiring to the coils, orange, blue, grey wiring to make sure that they are soldered to the correct lugs. It may be that your EOS is shutting off the low power coil and energizing the high power because they are wired incorrect.
Can you confirm the correct order?
Diodes may be bad too. May need to replace coils.

#32 5 years ago

On the point on the 7812 voltage regulator, which powers the optos, as mentioned from my repair guides. What it eludes to but doesn't actually say is that the C2 cap in circuit with the 7812 sometimes fails. This makes the 12 volts flutter which confuses the hell out of optos. this and bad "u" optics on the flipper boards can make a flipper coil hot. But as someone else said, also depends on your definition of "hot". Flipper coils will get warm from constant playing.

#33 5 years ago

I had a similar issue on a Creature once and ended up having to replace the LM339n comparator at U4 and at U6. If they start flaking out they can cause improper EOS readings and cause the high voltage side to pulse causing the coils to heat up among other things.

#34 5 years ago
Quoted from rygar:

Both flipper coils are overheating in my CFTBL. I have done the following things:
- replaced both coils with brand new ones,- swapped fliptronic board with working fliptronic board from my roadshow,- swapped flipper opto boards with working ones from my White Water,- replaced both EOS switches (also tested the game without EOS switches),- replaced transformer.
The coils are still overheating and they get too hot to touch after 15 or 20 minutes of play.
Any ideas what other things should I try?

ok, this is a Hail Mary,

(sometimes called A-B-A testing too)

put the suspect parts in your road show, and see if the problem follows the parts.

To others,
Please note the part I quoted where OP pulled boards from the Road Show.
Where are these LM339's that you think are suspect?

#35 5 years ago
Quoted from scott_freeman:

Where are these LM339's that you think are suspect?

On the fliptronics board.

LTG : )

#36 5 years ago

Hello.

Thank you for all your suggestions. Sorry for the late report, as I did not have the time to look at my CFTBL till today.
I have measured the coils temperature. On other machines the max temperature after playing them for 30 minutes continously is around 40 degrees C (104 F). ON this CFTBL the temperature is around 70 degrees C (158 F).
I have also tried to start the game and let it on for half an hour without flipping. The coil temperature did not rise in that case.

#37 5 years ago

ok, since you swapped the fliptronics board, (thanks lloyd for confirming it has the LM339s'),
your swap rules out the LM339's, and the rest of that board.

Ok, I'm back at mechanical binding.

Care to swap one complete flipper assembly bewteen your two games?

If your heat issue follows the assembly, you know where to focus.

I'm still thinking binding.

just a reminder, both the coil stop, and the small bracket holding the coil, need to be seated squarely. (90 degrees to the axial line of the coil)

Don't let either bracket walk/turn while tighting down their fasteners.

#38 5 years ago

This may have already been covered, but I had a similar problem with a Flintstones. Somebody had put two return springs on the flippers, and I just didn't notice it, and that caused them to get very hot.

#39 5 years ago
Quoted from scott_freeman:

ok, since you swapped the fliptronics board, (thanks lloyd for confirming it has the LM339s'),
your swap rules out the LM339's, and the rest of that board.
Ok, I'm back at mechanical binding.
Care to swap one complete flipper assembly bewteen your two games?
If your heat issue follows the assembly, you know where to focus.
I'm still thinking binding.
just a reminder, both the coil stop, and the small bracket holding the coil, need to be seated squarely. (90 degrees to the axial line of the coil)
Don't let either bracket walk/turn while tighting down their fasteners.

Thanks for the tip.

I will swap one complete flipper assembly and see what happens. I will also take pictures of current assembly to show.

#40 5 years ago
Quoted from 0geist0:

This may have already been covered, but I had a similar problem with a Flintstones. Somebody had put two return springs on the flippers, and I just didn't notice it, and that caused them to get very hot.

Thank you for your tip. Unfortunatelly that is not the case with this CFTBL. I have personally rebuilt the whole asembly per Vid 1900 instructions (http://pinside.com/pinball/forum/topic/vids-guide-to-upgradingrebuilding-flippers).

#41 5 years ago
Quoted from scott_freeman:

ok, since you swapped the fliptronics board, (thanks lloyd for confirming it has the LM339s'),
your swap rules out the LM339's, and the rest of that board.
Ok, I'm back at mechanical binding.
Care to swap one complete flipper assembly bewteen your two games?
If your heat issue follows the assembly, you know where to focus.
I'm still thinking binding.
just a reminder, both the coil stop, and the small bracket holding the coil, need to be seated squarely. (90 degrees to the axial line of the coil)
Don't let either bracket walk/turn while tighting down their fasteners.

Swapped one assembly today and it is ok when installed in RS and the RS one is overheating in CFTBL.

#42 5 years ago
Quoted from Big70:

I'd agree with the others to look at the flipper opto boards, but if you'd tried 3 sets (all of them with clean optos correct?), you can pretty well eliminate that as the issue. The next place would be to look at board issues, but you've eliminated board problems by swapping in good known working boards. If you've indeed already replaced the CPU, Driver board, flippertronics board, flipper opto boards, and even the transformer with known good working ones (plus new coils, EOS switches), you've eliminated all of them as the issue. That only leaves me to think you've got a wiring problem somewhere.
You might try swapping ribbon cables to eliminate those as an issue since they carry the data for the logic. Bad ribbon cables can cause all sorts of weird problems.

I have forgot to mention that I have swapped two ribbon cables (the one from driver board to CPU board and the one from CPU board to fliptronic board).

#43 5 years ago

I think I might be having same problem or similar on my T2. Just the right flipper.. Already replaced coil 1 time and was this way when I purchased machine. Cooked it again tonight. Was thinking flipper rebuilt but thinking otherwise after reading this thread.

#44 5 years ago
Quoted from kurtackerman:

Was thinking flipper rebuilt but thinking otherwise after reading this thread.

I'd go over your EOS points and be sure they open, and open soon enough in the flipper stroke.

This is different from the problem in this thread.

LTG : )™

#45 5 years ago
Quoted from rygar:

Swapped one assembly today and it is ok when installed in RS and the RS one is overheating in CFTBL.

ok, this should eliminate binding.

boards and LMM's were eliminated.

and the coils are cold when not played.

Now, I'm thinking your grounds are not good.
The problem needs to be with something that is common to the two flipper assemblies.

You should have zero voltage when measuring across your grounds.
Also, no AC ripple in the ground circuits (set DMM to ACC for this)

even more challenging, you need to measure across the grounds when the flippers are actuated.

oh, and just for the record, what version ROM are you running? (seeing if you have a prototype ROM)

#46 5 years ago
Quoted from scott_freeman:

ok, this should eliminate binding.
boards and LMM's were eliminated.
and the coils are cold when not played.
Now, I'm thinking your grounds are not good.
The problem needs to be with something that is common to the two flipper assemblies.
You should have zero voltage when measuring across your grounds.
Also, no AC ripple in the ground circuits (set DMM to ACC for this)
even more challenging, you need to measure across the grounds when the flippers are actuated.
oh, and just for the record, what version ROM are you running? (seeing if you have a prototype ROM)

Thank you. I will measure the voltage and report back. I have tried L-3 (on a CPU board which is currently in) and L-5 version, both with same results.

#47 5 years ago

I just read through this thread quickly but don't recall seeing this mentioned - maybe you have the hold coil and the power coil reversed at the lugs. Take a photo of your coils as installed on your CFTBL, then measure the voltages on the 3 terminals of the coil with the flipper energized and let us know what the voltage on each terminal is with respect to the terminals shown in your photo.

This almost has to be the problem - it's the only way the game could be playable with a known good fliptronics board and still have coils overheating.

#48 5 years ago

I think you're alright. Coils get warm, in fact hot to the touch in many cases, especially on games that play more low and down, such as CFTBL and IJ. I went through a similar thing with my IJ flippers a long time ago, and I cold not figure it out. It just seemed like to the touch, they were hotter than other coils of the same WPC era. In the end, I just attributed this to the game design, and that all in all, there are more flips on some machines than others.

Take LOTR for example. I know it's a different system, but it has some much more flipper action than most sterns, and because of this is suffers more than any other machine with this same issue, coils working fine but heating up. In that case, the heat is enough to unglue the stickers for the coils. People have done all kinds of crazy mods from heatsinks to computer fans to deal with that machine. Different design altogether, but its to show that flippers can have this happen, and it's acceptable all in all.

Try taking another WPC89 flip II game you have and starting each cold, and say for the left flipper only, flip each 100 times, measure the heat with whatever you are using, then 200 times. I'm guessing this will come out to be close.

CFTBL sees a lot of quick and low play. It's hard to realize how many more times you might be flipping, but take a worst case scenario of you constantly flipping one flipper coil fast for a while, it's going to get quite hot on any machine.

#49 5 years ago
Quoted from yonkiman:

I just read through this thread quickly but don't recall seeing this mentioned - maybe you have the hold coil and the power coil reversed at the lugs. Take a photo of your coils as installed on your CFTBL, then measure the voltages on the 3 terminals of the coil with the flipper energized and let us know what the voltage on each terminal is with respect to the terminals shown in your photo.
This almost has to be the problem - it's the only way the game could be playable with a known good fliptronics board and still have coils overheating.

this is possible,
Keep in mind, he recently swapped the assembly from the road show, to the Creach.

I think this possibility can be tested in the flipper test menu (if this game has that)

I know in later produced WPC games, there is a flipper test that actuates each of the circuits (high left, low left, high right, and low right)

#50 5 years ago
Quoted from yonkiman:

I just read through this thread quickly but don't recall seeing this mentioned - maybe you have the hold coil and the power coil reversed at the lugs. Take a photo of your coils as installed on your CFTBL, then measure the voltages on the 3 terminals of the coil with the flipper energized and let us know what the voltage on each terminal is with respect to the terminals shown in your photo.
This almost has to be the problem - it's the only way the game could be playable with a known good fliptronics board and still have coils overheating.

Hello.

I am attaching a pic of the right coil. I hope that it is wired incorrectly so that would solve the heat problems.

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