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.

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 : )

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

Your problem lies elsewhere.

LTG : )

Good call LTG, mis-diagnoses on my part.

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.

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

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?

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

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.

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.

hi rygar,did you look at the coils?

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 : )

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'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.

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.

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.

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?

On the fliptronics board.

LTG : )

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.

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.

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.

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 : )™

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)

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.

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.

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)