F-14 Tomcat blows solenoid fuse when multiball starts

I recently purchased an F-14 Tomcat. It was working fine when I played it at the location, but after I took it home it seems to blow a fuse when multiball starts.

I was hoping someone could give me some troubleshooting techniques to pinpoint the problem without having to go through a ton of 2.5 Amp slow blow fuses.

I've gone through the coil tests and everything seems to fire fine on it's own. However, when I get multiball something goes amiss. The initial "here they come" starts up, but then Congratulations starts blinking on the display and it blows a fuse.

It looks like this doesn't have the original driver board. Instead it's a Kohout Enterprises board. The fuse that keeps blowing is on that board in the F2 spot (solenoid). I attached a picture of the board.

kohout_board (resized).jpg

#2 5 years ago

JON

ezelljon

Pinside member

6y 50,100 150 21

I don’t have an f14, but had a similar issue with my SOF.

My first guess would be it’s one of the solenoids that kicks out during the MB (F14 has like three diff ones doesn’t it?)

Check the schematic, see what solenoids or flashers are on that fuse. Get a multimeter, measure the resistances of those solenoids and bulbs, you’ll probably find one that’s too low or not continuous (manual should include what values should be), if so, replace it.

#3 5 years ago

ZDG

gutz

Pinside member

^^^ could be one of the three kickers. To isolate which one, go into attract mode with a good fuse installed (or better yet a circuit breaker). Take a ball from the trough and drop it into the left kick out. The ball should be ejected immediately. Repeat several times to see if the fuse blows. If not, move to the next one and repeat.

Edit: you said coil test works fine, hmm. If you lock three balls then drain ball 3 - does the fuse blow when the game ejects all the balls? Or maybe try unhooking your beacons and see if multiball start blows the fuse.

#4 5 years ago

DBW

Crater

Pinside member

Quoted from gutz:
^^^ could be one of the three kickers. To isolate which one, go into attract mode with a good fuse installed (or better yet a circuit breaker). Take a ball from the trough and drop it into the left kick out. The ball should be ejected immediately. Repeat several times to see if the fuse blows. If not, move to the next one and repeat.
Edit: you said coil test works fine, hmm. If you lock three balls then drain ball 3 - does the fuse blow when the game ejects all the balls? Or maybe try unhooking your beacons and see if multiball start blows the fuse.

So three things...
First, thanks for the tips! I'm a little out of my league right now.
Secondly, I went back over the coil and flasher tests. This is probably a red herring, but flasher 3 is out. I embarrassingly don't even know how to get to it because I've never owned this era of machine, and you can't slide out the playfield like I am normally used to. I attached a picture of the back flashers with flasher 3 circled.
Thirdly, I unattached the beacons and tried starting multiball and sure enough it was fine. Does that necessarily mean that something related to the beacon is causing the issue, or is this also a red herring? I checked all the solenoids and diodes and they seem* fine.

So presumably I may be able to play the game without the beacons, but I should probably track down this issue in case it's something else and I'm the game is just a ticking time bomb at the moment.

Any further suggestions?

flasher3_LI (resized).jpg

#5 5 years ago

JON

ezelljon

Pinside member

6y 50,100 150 21

Are you using incandescent GI and insert bulbs? What about the flashers? My sys 11 was resetting during the light show jackpot freak out until I swapped out the GI and inserts for LEDs. Kept the incandescent flashers tho because I think Sys11s require modification for LED flashers. If you’re feeling lost I’d try to find someone in your area who knows system 11s and ply them with booze; I’m sure there are plenty of techs in Seattle area who can help you.

#6 5 years ago

desertT1

Tucson Pinball

Vail, AZ

12y 72,550 4,032 23

Instead of going through fuses tracking the issue down, get a circuit breaker of the same rating and solder a fuse on. Will save money in the long run, but will also avoid running out of fuses and having to stop if you haven’t found the issue yet.

#7 5 years ago

DBW

Crater

Pinside member

Quoted from ezelljon:
Are you using incandescent GI and insert bulbs? What about the flashers? My sys 11 was resetting during the light show jackpot freak out until I swapped out the GI and inserts for LEDs. Kept the incandescent flashers tho because I think Sys11s require modification for LED flashers. If you’re feeling lost I’d try to find someone in your area who knows system 11s and ply them with booze; I’m sure there are plenty of techs in Seattle area who can help you.

This machine does indeed have incandescent GI and flashers. I could certainly swap them out for LEDs. I probably would have anyways. I will get on that.

Quoted from desertT1:
Instead of going through fuses tracking the issue down, get a circuit breaker of the same rating and solder a fuse on. Will save money in the long run, but will also avoid running out of fuses and having to stop if you haven’t found the issue yet.

This is a cool trick. I'm going to try it. Thanks!

Since the game appears to be working, and I have some directions to go in, I'm going to resolve this one for the moment. Thanks for the help!

#8 5 years ago

MIK

statictrance

Skill Shot Repair

Upper Saint Clair, PA

8y 56,850 662 35 7

If you need to swap out incandescent to LED, you're leaving an issue that you should probably resolve.

That's very odd that the beacon detachment allows MB to function - cause doesn't the beacon activate as soon as you lock ball three? Beacons would already be on before that solenoid kick.

My next guess would be to try starting a game with the glass off and dropping a ball directly into the three kickers - see if any of those trip your fuse on their own outside of multi ball - that might get you a solenoid/wire to look into.

Alternatively - get the beacons lit and try other controlled/switches solenoids to see if it's an issue there (like light them and try the kickback or Jagov)...

#9 5 years ago

ZDG

gutz

Pinside member

What does the manual call for at F2? The online manual says 4a sb, but I can't see it in full detail. I can double check mine tonight. The Kohout board might be labeled so it can work in any system 11, but not all the solenoid fuses will be the same - it depends on the game.

#10 5 years ago

ZDG

gutz

Pinside member

OP
Quoted from Crater:
This machine does indeed have incandescent GI and flashers. I could certainly swap them out for LEDs. I probably would have anyways. I will get on that.

I encourage you to hold off on the LEDs. It has nothing to do with your issue and you should solve one problem before creating another

#11 5 years ago

ZDG

gutz

Pinside member

Quoted from statictrance:
If you need to swap out incandescent to LED, you're leaving an issue that you should probably resolve.
That's very odd that the beacon detachment allows MB to function - cause doesn't the beacon activate as soon as you lock ball three? Beacons would already be on before that solenoid kick.
My next guess would be to try starting a game with the glass off and dropping a ball directly into the three kickers - see if any of those trip your fuse on their own outside of multi ball - that might get you a solenoid/wire to look into.
Alternatively - get the beacons lit and try other controlled/switches solenoids to see if it's an issue there (like light them and try the kickback or Jagov)...

The beacon is on before multiball starts. The beacon alone isn't blowing the fuse. The kickouts probably won't be the problem either if they don't blow the fuse during the solenoid test. The beacons + kickouts + flashers is pulling too much current at the start of multiball. Its easy to overlook the beacons as a problem, but they are a 'solenoid' too.

Of course this is all moot, if there is a 2.5a fuse where a 4a fuse should be

#12 5 years ago

JON

ezelljon

Pinside member

6y 50,100 150 21

Quoted from statictrance:
If you need to swap out incandescent to LED, you're leaving an issue that you should probably resolve...

Yes, you are certainly correct on that, but in my case it solved a problem I think was related to an aftermarket power board (but who knows? All stuff currently checks out with DMM fingers crossed).

#13 5 years ago

ZDG

gutz

Pinside member

From the insert panel

20180905_192455 (resized).jpg

1 month later

#14 5 years ago

DBW

Crater

Pinside member

http://www.pinballpcb.com/Sys7-11bPowerSupply.htm

For posterity, I figured I should follow up on this particular issue. The real issue seemed to be the power driver board I was using. Let this be another warning to always make sure you are using original boards when buying a new pinball machine, because you just never know what you're getting when you see an after market replacement board on one of these machines.

In particular this machine was using a "Kohout Enterprises" replacement board. They have a website with the board information still while I'm writing this, but I don't know how long it will stay up because the product no longer exists:

The compatibility chart does indeed show F-14 Tomcat on the list of supported games, but after going through all the circuitry and double checking all the connectors, I've found that this isn't the case. The 2.5 Amp fuse always blows, and I ended up getting a Rottendog replacement just to see if I found a difference. It turns out there is a big difference, because the Rottendog works fine and I can finally play this machine without worrying that I'm going to blow a fuse.

My conclusion is either the particular Kohout board that was on it was flawed, or it just doesn't actually support F-14 Tomcat. Either way, I appear to have a working machine now.

#15 5 years ago

BOY

vid1900

Pinside member

Sana'a

12y 169K 40,234 18

OP
Quoted from Crater:
My conclusion is either the particular Kohout board that was on it was flawed, or it just doesn't actually support F-14 Tomcat. Either way, I appear to have a working machine now.

I'm sure it did (past tense) support F14, but simply malfunctioned.

A bridge rectifier or diode shorts, and it will keep blowing fuses.

Glad you got it working!

#16 5 years ago

ZDG

gutz

Pinside member

Quoted from gutz:
...
Of course this is all moot, if there is a 2.5a fuse where a 4a fuse should be

Quoted from gutz:
From the insert panel
[quoted image]

Quoted from gutz:
What does the manual call for at F2? The online manual says 4a sb, but I can't see it in full detail. I can double check mine tonight. The Kohout board might be labeled so it can work in any system 11, but not all the solenoid fuses will be the same - it depends on the game.

Did you ever put in a 4 amp sloblow fuse like the f14 manual says should be installed at F2?

#17 5 years ago

DBW

Crater

Pinside member

Quoted from gutz:
Did you ever put in a 4 amp sloblow fuse like the f14 manual says should be installed at F2?

hmmmm....

So I didn't put a 4 amp fuse in the F2 slot. The Kohout board specifically calls out a 2.5 amp fuse there. I guess that could be the issue. I see what you're saying with the solenoids on F14 in particular might require that to be 4 amps. I didn't see that anywhere in the Kohout manual and I assumed the board would have spelled that out for me in the instructions because it is quite a different board compared to the original.

Maybe I can reuse it in the future then! Thanks for the ideas everyone.

#18 5 years ago

ZDG

gutz

Pinside member