New! Dark mode!

Browsing Pinside at night? Getting tired of all the white? Switch to dark mode using the button in the top right (or CTRL-B)!

(Topic ID: 266512)

Firepower pop bumper continually firing


By creativenuts

5 months ago



Topic Stats

  • 48 posts
  • 13 Pinsiders participating
  • Latest reply 5 months ago by uphamj
  • Topic is favorited by 1 Pinsider

You

Linked Games

Topic Gallery

There have been 10 images uploaded to this topic. (View topic image gallery).

Inkedunnamed (3)_LI (resized).jpg
unnamed (2) (resized).jpg
Inkedunnamed (1)_LI (resized).jpg
unnamed (4) (resized).jpg
unnamed (3) (resized).jpg
441935802.png
cut wires (resized).jpg
unnamed (1) (resized).jpg
unnamed (resized).jpg
0AD41982-9AB2-40F7-80D0-43CFC4DE4A7A (resized).jpeg

#1 5 months ago

Ive just got round to replacing the power board in my Williams Firepower with a Rottendog replacement, I had tried replacing components on the original power board which worked for a while but want doing the job properly.
Now when I start a game or go into test mode, one of the pop bumpers continually fires. ive checked the mechanism but all seems good. Ive tried reseating the connectors on the driver board (also a Rottendog replacement) . anyone have any thoughts on what to try next? thanks

#2 5 months ago

Possible vibration of the pin causing the switch to close? If you widen the gap of the pop bumper switch under the playfield does it stop?

Check the diode on the coil as well. Does it also have a capacitor on the switch? shoot a pic and post.

#3 5 months ago

Ghost.

0AD41982-9AB2-40F7-80D0-43CFC4DE4A7A (resized).jpeg
#4 5 months ago

so today the pop bumper seems ok (without me having done anything) however one of the other pop bumpers is now playing up. as soon as the machine is switched on it locks on , see attached pic. the one on the right . Ive checked the switches under the playfield but they look fine.
As I said before the driver board and now the power board are both rottendog replacements. Ive tested the coil with a multimeter and the resistance is ok.
Any suggestions welcome.

unnamed (resized).jpgunnamed (1) (resized).jpg
#5 5 months ago

That coil looks shot, notice the burn on the label. I’d start there. Disconnect it and reevaluate

#6 5 months ago

Ive disconnected that coil and now none of the pop bumpers work. also the kicker for the ball retainer at the top doesnt work either.
makes me wonder if the new power board is causing problems.

#7 5 months ago

Those pop bumpers are all on the same column in the switch matrix and the upper right eject hole is on the same row as the bottom right pop bumper. Which pop bumper did you disconnect? Cannot tell from the picture.

#8 5 months ago
Quoted from creativenuts:

Ive disconnected that coil and now none of the pop bumpers work. also the kicker for the ball retainer at the top doesnt work either.
makes me wonder if the new power board is causing problems.

One of the lugs on the coil had 2 red wires wires. That is the power side and they are wired from one coil to the next. If you just cut the 2 red wires off the coil, you broke the power supply chain to the downstream coils which will stop them from working.

Connect the wires back up to the coil.

Check the problem still exists.

Remove J13 from the driver board. This is the special switch input connector (fires the pops, slings, etc).

If the coil still locks on, you have a problem with the driver board.

If the coil does not lock on, the problem is in the trigger switch or wiring.

#9 5 months ago
Quoted from Schwaggs:

One of the lugs on the coil had 2 red wires wires. That is the power side and they are wired from one coil to the next. If you just cut the 2 red wires off the coil, you broke the power supply chain to the downstream coils which will stop them from working.
Connect the wires back up to the coil.
Check the problem still exists.
Remove J13 from the driver board. This is the special switch input connector (fires the pops, slings, etc).
If the coil still locks on, you have a problem with the driver board.
If the coil does not lock on, the problem is in the trigger switch or wiring.

Following. I'm have the same issue with Top Right Jet bumper. I cut the blue/orange wire and I have now issues with game booting up. It plays fine. The board was just serviced too and never had that issue of locking up. I'm going to change the coil out and add some new parts to the jet bumper and see if that fixes the issue. Please share if you are able to fix this on your machine. Btw it's J12 that you need to unplug for those bumpers.

#10 5 months ago
Quoted from XavierTheXMan:

Following. I'm have the same issue with Top Right Jet bumper. I cut the blue/orange wire and I have now issues with game booting up. It plays fine. The board was just serviced too and never had that issue of locking up. I'm going to change the coil out and add some new parts to the jet bumper and see if that fixes the issue. Please share if you are able to fix this on your machine. Btw it's J12 that you need to unplug for those bumpers.

J13 is the switch input to the driver board for special solenoids.
J12 is the drive.

When trying to troubleshooting a locked coil, disconnecting the switch input connector, J13 can isolate the problem to the board or the switches. Disconnecting J12 only disconnects the drive transistor from the solenoids stopping the coil from locking on but really doesn't tell you anything.

#11 5 months ago
Quoted from Schwaggs:

J13 is the switch input to the driver board for special solenoids.
J12 is the drive.
When trying to troubleshooting a locked coil, disconnecting the switch input connector, J13 can isolate the problem to the board or the switches. Disconnecting J12 only disconnects the drive transistor from the solenoids stopping the coil from locking on but really doesn't tell you anything.

Thank you for the clarification. Can you tell me the steps to check if it's the board or the switches? I appreciate the help in trying to locate the issue.

#12 5 months ago

Thanks everyone for your help so far. Of all the forums I have been on for other things (software etc) Pinside is by far the quickest, friendliest and most helpful.
I did indeed just cut the wires to the locked on pop bumper. see attached pic, its the bottom left one. the kicker that it put out of action too is the one at the top (with a foam ball blocking it so my kids could have a game without the ball getting stuck!)
I was just beginning to realise that they must be wired in series.

will give an update later

cut wires (resized).jpg
#13 5 months ago

so. I reconnected the pop bumper coil

with J13 removed the bumper still locks on as soon as the machine is turned on
with J12 removed it doesnt lock on (and obviously none of the other bumpers kickers work too)

Does this mean its not the board but its the switches?
whats confusing me is that the coil locks on as soon as the machine is turned on where as the other bumpers dont work until the game is started.
Ive tested the resistance of the coil and it reads the same as the others.

#14 5 months ago
Quoted from Schwaggs:

Remove J13 from the driver board. This is the special switch input connector (fires the pops, slings, etc).
If the coil still locks on, you have a problem with the driver board.

As Shwaggs stated in post 8....

#15 5 months ago

Cool, so taking J13 off the driver board you eliminated the pop bumper switch from the list of suspects. That leaves us with J12, the ground path for the special solenoids (including the pop bumpers and probably the slingshots). The fact the coil is activating the moment you turn the game on with J12 plugged in tells us the pop bumper is getting a path to ground the instant the game is turned on. That usually indicates a bad/shorted driver transistor and/or pre-driver transistor on the driver board. You can test them both using the diode test on your meter. Looking at the schematic, the driver transistor is Q4, pre-driver is Q3. The lower left pop bumper is labeled solenoid 18, you can trace it on the schematic from the coil to 2J12 pin 4. There should be a blue wire with a red stripe at that connector--that's the ground wire coming from the pop bumper coil under the playfield. The transistors on the driver board provide the path to ground for the coil, and when they go bad, they will often cause a coil to lock on immediately upon turning on the game.

To summarize: the red wire at the pop bumper coil is the +28vdc supply. The blue/red wire on the other lug of the pop bumper is the ground wire, which runs up to the driver board at 2J12, pin 4. From pin 4, the ground circuit for the pop bumper continues to a TIP120 transistor (Q4).

When the mpu activates that transistor, it completes the path to ground for the coil and the coil fires (pop bumper pops). While I'm not necessarily recommending you do this, here's an easy way to demonstrate what's happening on a simpler level. If you remove the blue/red wire from 2J12 pin 4, the pop bumper should stop locking on. If you then stripped the end of that wire and *very briefly* touch the exposed end of the wire to the ground strap in the backbox, it will activate the coil. The transistor is acting like a switch in a way, when it gets activated it momentarily provides a path to ground. A bad or shorted transistor will often "stay on" causing the coil to lock on the moment you turn the game on. Note the TIP120 is the likely culprit but there are other components in that circuit that can go bad in addition to the TIP120 transistor... the pre-driver transistor, the chips before that, the diode on the coil, etc. Good luck!
441935802.png

#16 5 months ago

Excellent logic explanation Frunch.

#17 5 months ago

Thats a really clear explanation frunch . Thanks for your help. will let you know how I get on.

#18 5 months ago

even before getting my multi meter on it I can see that TIP120 transistor (Q4) looks different to the others and looks a bit burnt out.

unnamed (3) (resized).jpg
#19 5 months ago

so, Im trying to find a replacement transistor . I should be looking for FQP 13N1OL should I ? or TIP 120 (or is it the same thing).
Im in the UK so hoping to find somewhere at least in Europe. Im only managing to find transistors for sale on Ebay so far (and usually delivered from China).

unnamed (4) (resized).jpg
#20 5 months ago

You're welcome!

TIP120 or even better a TIP102 are both suitable replacements. I would recommend checking Q4 and Q3 with your meter on diode test. I'll admit, it definitely looks like Q4 fried. Are you familiar with the procedure for testing transistors?

Scratch that--you have a rottendog board. I am not sure if those transistors are suitable. Do you have the schematic for the driver board?

#21 5 months ago
Quoted from creativenuts:

I should be looking for FQP 13N1OL should I ?

The factory Williams board uses TIP120 transistors. But these Rottendog boards use MOSFET transistors which are different, the part number is FQP13N10L (that's "one zero L" not "one oh L") that you need.

https://www.ebay.co.uk/sch/i.html?_from=R40&_nkw=FQP13N10L&_sacat=0&_dmd=1&rt=nc&LH_PrefLoc=1

#22 5 months ago

Before replacing the transistor be sure to ohm check the coils that were locking on (pop bumper coils). They should all show a similar value. Anything that shows below 2 ohms or shows over limit or way out of whack from other similar coils is a bad coil and needs to be replaced. Even though the transistor at Q4 is likely to have caused the original problem, a shorted coil in that series may burn up your newly installed transistor and create more work!

You said you replaced mpu and power supply so I am assuming you still have original driver board in the game?

Be sure your coils are ok then replace transistor. If anything still locks on after you check that coils are ok and replace Q4, turn game off, check resistance at the coil and then look for another bad transistor (hopefully that doesnt happen!).

Good luck. Firepower is a cool game!

#23 5 months ago
Quoted from creativenuts:

so, Im trying to find a replacement transistor . I should be looking for FQP 13N1OL should I ? or TIP 120 (or is it the same thing).
Im in the UK so hoping to find somewhere at least in Europe. Im only managing to find transistors for sale on Ebay so far (and usually delivered from China).[quoted image]

I would replace it with another 13N10L MOSFET.

Before you do, check the resistance of that coil. It should be around 5.3 ohms. If you get zero or close to it, reverse the polarity of the meter leads and measure again.

If the coil resistance is good, make sure to replace the diode on that coil and make sure it is installed in the correct orientation. I suspect the diode is bad and what killed the MOSFET.

#24 5 months ago

thanks.

the Rottendog MPU replacement is actually an MPU / Driver board, so currently its only the sound board thats original behind the backglass. Im keeping the old original boards inside the cabinet anyway in case anyone wants to restore it in the future. Ive had this Firepower 25 years, the only electronics I do is when tinkering with it which is why I rely so much on the amazing knowledge on this forum!!
Ive checked resistance of the coil and it measures the same as the others. Ive ordered some more transistors and already have plenty of diodes, so I should be good now I think im getting to the route of the problem. will post updates.

#25 5 months ago

Buy some extras so you will have some on hand the next time you need them.

#26 5 months ago

Thanks guys for helping creativenuts. The info you all are providing is helping me as well. Frunch - Appreciate the explanation for this newbie. Schwaggs - Thanks as well for the steps as well.

I hope you guys don't mind if I chime in with questions or should I start my own thread?

#27 5 months ago

Might be better to start a new thread just to keep things orderly for OP.

I'd be happy to try to help you further, as I'm sure many others will be as well.

#28 5 months ago

Hi,
So my mosfet transistors have arrived. Im trying to remove the old one from the rottendog circuit board and at the risk of sounding like a complete noob I cant remover it.
Im going carefully as Im worried about damaging things. Ive worked with a soldering iron a few times before but its not a regular hobby for me.
Te soldering iron is definitely hot enough but is there a knack to removing a component with three pins? Im heating all three up but it just wont budge,

any tips appreciated

#29 5 months ago

ignore me. its out! soldering iron tip that flat and does all three at once!

#30 5 months ago

Nice, glad you managed to remove the old one ok. Any update?

#31 5 months ago

getting there, had to take a break to exercise the kids! going to replace the coil and diode too so may be a while.....

#32 5 months ago

Take your time! Just anxious to see if that's the solution.

#33 5 months ago

but seeing as you are there.... can you tell me where to start when replacing the coil, ive done it before about 5 years ago and it was a bit trial and error then , but totally forgotten now!

is it the screws at A or the nuts at B? thanks

Inkedunnamed (1)_LI (resized).jpg
#34 5 months ago
Quoted from creativenuts:

but seeing as you are there.... can you tell me where to start when replacing the coil, ive done it before about 5 years ago and it was a bit trial and error then , but totally forgotten now!
is it the screws at A or the nuts at B? thanks[quoted image]

Next transistor you need to remove, try cutting the body of the transistor off the legs first. Then you can desolder and remove one leg at at time.

Remove the 3 nuts that hold the coil bracket to the bottom of the playfield. be careful to catch the spring on the plunger as you remove the bracket.

Once that is removed, you remove screws "A" and you can remove the old coil and mount the new coil and sleeve in place.

Reverse above (remember the spring) to reassemble.

#35 5 months ago
Quoted from Schwaggs:

Next transistor you need to remove, try cutting the body of the transistor off the legs first. Then you can desolder and remove one leg at at time.

That makes total sense!

thanks for the coil info, im on it now

#36 5 months ago

Lot's of great infomation on this thread.

I wonder sometimes if pinsiders have way more knowledge just from working on their machines... figuring things out.. getting tips/info from other pinsiders than the guys that had routes & worked on machines on a daily basis?

#37 5 months ago

Oh, one other thing:

Make sure your new coil has a diode installed. Pay careful attention to the lugs you solder the wires - Double red wire (power supply) goes to the lug with the banded side of the diode.

#38 5 months ago

ok for my next question...... solder coils (im replacing two) and then reassemble mechanism. or reassemble then solder?
Im thinking the first route . probably doesnt make much difference but wondering if anyone has preference

unnamed (2) (resized).jpg
#39 5 months ago
Quoted from Schwaggs:

Make sure your new coil has a diode installed. Pay careful attention to the lugs you solder the wires - Double red wire (power supply) goes to the lug with the banded side of the diode.

thanks yes, i bought with diode attached and took photos before removing old coils to make sure i put back correctly.

#40 5 months ago

me again...!! confused now. the top right coil im replacing has the doide going the opposite way to the way I think it should go. Im thinking it should be the same as the top left pop also in the image.

Inkedunnamed (3)_LI (resized).jpg
#41 5 months ago

so should I wire up according to the diode direction , which is the opposite to the way to the coils that were in there, or take off the diode and turn it around?

#42 5 months ago

All that matters is that the wires go to the correct sides of the diode. The diode can point either way, but again it's very important you put the wires on the correct sides of the diode (the banded side vs non-banded side).

#43 5 months ago

YES!!"!! all working now. A huge thankyou to everyone for talking me through this. not that I can get to play it yet as my kids are on it now!!!

#44 5 months ago

Awesome! Congratulations on the fix!

#45 5 months ago

Great stuff!! Enjoy!

#46 5 months ago

That's awesome!! Great work.

#47 5 months ago

Great work!

#48 5 months ago

Love it when a pin is back up and working. Congrats

Promoted items from the Pinside Marketplace
1,100
Sale Pending!
Sturgeon Bay, WI
$ 11.00
$ 499.95
Lighting - Led
Pin Stadium Pinball Mods
From: $ 40.00
Cabinet - Other
Rock Custom Pinball
From: $ 5.00
Cabinet - Other
UpKick Pinball
$ 14.00
Electronics
Yorktown Arcade Supply
From: $ 20.00
Cabinet - Other
Rock Custom Pinball
From: $ 5.00
Cabinet - Other
Rock Custom Pinball
From: $ 5.00
Playfield - Toys/Add-ons
UpKick Pinball
$ 259.95
Lighting - Led
Pin Stadium Pinball Mods
From: $ 9.00
From: $ 18.00
Apparel - Men
Pinside Shop
$ 12.00
Cabinet - Other
Siegecraft Electronics
$ 33.00
Playfield - Decals
Metal-Mods
$ 399.95
Lighting - Led
Pin Stadium Pinball Mods

Hey there! Got a moment?

Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside