(Topic ID: 4918)

Bally 1978 Power Play Pinball - Keeps Blowing Fuse

By Mickey0902

8 years ago

Topic Stats

  • 39 posts
  • 9 Pinsiders participating
  • Latest reply 10 months ago by silver_spinner
  • Topic is favorited by 3 Pinsiders


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#1 8 years ago

I was playing the pinball machine yesterday and the pinball shut completely off during play. I checked the fuses and one was blown. I replaced it with a new fuse and every time I hit the power on button, the fuse blows again. The fuse is a 250V fuse (AGC 3A).

Does anyone have an idea on what could be causing this?

Let me know. Thanks.

#2 8 years ago

Most likely the power control board needs to be rebuilt. This is very common. The bridge rectifiers are over 30 years old now and were only meant to last about 10. If you can solder this is not a difficult board to repair. You can buy a kit with all the parts from http://www.bigdaddy-enterprises.com/ for about $16. Look under power supplies and choose the kit for the power board your game uses. Recommend you replace the connectors too.

Or you can buy a new board from www.pin-logic.com.

If you buy a new board don't throw away the old one. It is probably still good and can be repaired.

#3 8 years ago

Hey Mick see if you can post a few photos of the boards ,
some of the members are pretty sharp and may see something not right
you would be surprised how much a photo helps

#4 8 years ago

Okay thanks SealClubber. I will take a look at the boards on those sites. Hellodeadcity, I will take some pics of the boards tomorrow and post them. Thanks for the help.

#5 8 years ago

If that is the main line fuse, then its most likely the varistor (red disk device) that attaches to where the line cord comes into the game. The lead may have broken off, or if you had a power surge lately it gave its life to save your boards...

#6 8 years ago

The main line fuse should be an 8A and if the varister was shot I thought the game would not get any power.

#7 8 years ago

Ok so probably a shorted Bridge rectifier like you mentioned earlier.

#8 8 years ago

Please see the pictures attached. I took a close up of the board where the fuse keeps blowing.

IMAG0430.jpg IMAG0431.jpg IMAG0432.jpg

#9 8 years ago

You are right Craigmack. Look inside the lower cabinet, in the back left should be a nice red disk shaped varister over a small silver box. This is where the power cord comes in from the wall. If it looks burnt, that is your problem.


When I blew a varister the game would not even turn on but I think the line filter was shot too.
Hopefully this is the problem as it is an easy and cheap fix.

#10 8 years ago

Hey, below is a pic of the red varister. It didn't look discolored. Would it be on the actual wires or the red portion be burnt?


#11 8 years ago

That varistar is perfect, you would know if it was bad...not only would it be black (and broke) but so would the wood behind it.

#12 8 years ago

Guess you need to pull the rectifier board and test your bridges. The varistor as mentioned above is fine. Next stop in the chain is the transformer, but they rarely go bad so its off to the rectifier board. You can test the bridge rectifiers with your DMM.

#13 8 years ago

The game doesn't even come on. As soon as I hit the button on the bottom of the game, the fuse blows. I'm not sure how I can check the board if I can't get power? Let me know what you think.

#14 8 years ago

I have just been looking at the manual and schematics of my Bally Silverball Mania which uses the same Rectifier board AS-2518-18.

That fuse which you have removed in your photo - is it labelled F6, a 3 amp slow blow fuse, this is the one that blows, correct?

This fuse is in the circuit for the primary windings of the transformer, and supplies mains power to the transformer for the whole game. Have you tried looking at the transformer itself for any melted or bubbling wax on the windings? Does the transformer itself smell burnt? Are there any shorted or damaged terminals on the transformer? Are the other fuses the correct value, especially the fuse for the High Voltage circuit for the displays (F2 - 0.75 amp) ? I had the wrong rating fuse in my Bally Vector with a shorted rectifier diode on the HV circuit for the displays, and the transformer windings started to get very hot without blowing the fuse before I noticed/heard the windings bubbling away!

As you have been playing the game before I assume the transformer is set up for the correct mains voltage (115 or 120 volts in your case). Hope this all helps!

#15 8 years ago

also this may sound too simple but check the line cord that plugs into the wall outlet
as well as the outlet

#16 8 years ago

There is a slight tear in the cord but it's been like that since I've had the game. Not sure if this could be causing it. I did wrap it in electrical tape but it still is blowing the fuse.


#17 8 years ago

It's hard to see in this picture but there is a green wire that I found not connected to anything on the inside of the door. It appears to be going to the start button on the outside of the door.


#18 8 years ago

These are the harnesses that connect to the transformer. They appear slightly burnt on the plastic area. I did notice this awhile back but the game was still functioning. Also, I do recall that during the play before, some lights on the game would go on and off during the play. I would open the cabinet and jiggle this harness and it would fix the problem. What do you think?


#19 8 years ago

This is a closer picture of the transformer. It has slight burn marks in the area where the harness connects.


#20 8 years ago

Lastly, I unplugged all the harnesses from the bottom cabinet to the top cabinet and replugged. I then connected an extension cord and plugged into a different outlet. Right when I plugged it in, a new fuse blew again.

#21 8 years ago

Check to make sure none of your transformer lugs are touching, I had two on my SS that were able to move freely and were bumped into each other.. of course, this blew the main fuse, but worth a shot. That harness certainly doesn't look like a good sign.

And really, you opened the cabinet while the game was on and jiggled a random harness to get the lights to work again... dude..

#22 8 years ago

Those connectors aren't slightly burnt, they are burnt. Need to be replaced along with the pins. Those burnt pins are the GI lighting power and return lines. Are you using #47 bulbs in the GI?
Note, this should have nothing to do with the fuse problem.

The power comes in thru the power cord, thru the varister and line filter, into J2 connector pins 6 and 7, thru the Fuse F6, to the tranformer. If F6 immediately blows you have a short in the main 110 volt AC power circuit. Check the varistor and the line filter in the cabinet.

So either the plug, cord, varister or filter are bad.

#23 8 years ago

replace the power cord Mick.

I think the green wire on the coin door photo goes to the coil below it,
it's common to have the signal wire cut to stop the loud buzz that sometimes develops over the years on those relays - not a big deal on the home front.
That coils job is to give back a coin whenever a coin drop on a pin with no power or off,
when it's on the coil pulls in and coins are directed to the coin mech. /acceptors

#24 8 years ago

replace the power cord Mick.

Yes, that cord certainly needs replacing. It won't cause the F6 fuse to blow though.


I think the green wire on the coin door photo goes to the coil below it,
it's common to have the signal wire cut to stop the loud buzz that sometimes develops over the years on those relays - not a big deal on the home front.
That coils job is to give back a coin whenever a coin drop on a pin with no power or off,
when it's on the coil pulls in and coins are directed to the coin mech. /acceptors

Agreed, those coils are often disconnected on the coin door for that reason.

The Varistor is in the circuit before the F6 fuse and the main cabinet on-off switch, so would blow the fuse in the mains plug if it was faulty.

Mickey0902, are you using the correct type fuse? You need a slow blow or anti-surge fuse in F6, as there will be a brief heavy current surge when the machine is switched on that will blow a normal fast fuse. Googling AGC3 fuses brings up a fast acting fuse.

#25 8 years ago

I just went and bought 4 of the slow blow 3A fuses. The same thing happened but the lights came on for a second and the game made a buzzing noise like it was going to kick on. Tried 2 of these fuses and they both blew.

#26 8 years ago

what could buzz like that?
is it (sound) coming of the PF? a locked coil?

#27 8 years ago

Hmmm, I think you may need to buy a few more of those SB fuses...........

All I can now suggest by looking at the schematics of Silverball Mania, is unplugging J1 and J3 on the Rectifier Board and seeing if the fuse still blows. If it still blows try removing all the fuses bar F6 on the Rectifier Board with J1 and J3 still unplugged. That will leave just the transformer and the Rectifier board in circuit. If it still blows, take the rectifier board off the cabinet and have a look to see if anything has shorted out on the back of the board to the metal cabinet. You'll need to pinch together the bases of those plastic pegs to release the board. After that it looks like a blown transformer.

1 week later
#28 8 years ago

I removed the transformer partially so you can see the back of the board. Will I be able to tell if the board is bad by the looks?


#29 8 years ago

Are there any burn marks on the metal heatsink behind where the circuit board normally sits?

Do any of the wires on the back of the board have damaged insulation where they could have been trapped, or whiskers or strands of wire touching another track on the board? Any smell or signs of burning on the back of the board?

#30 8 years ago

The first picture shows some black on the heat sink behind the board. Most of it could be wiped off by hand. The second picture shows after removing some of the black.

IMAG0450.jpg IMAG0451.jpg

#31 8 years ago

It just looks like 35 years of dirt on the heatsink to me. The back of the board and the heatsink look OK from what I can see in the photos.

Refit the board to the heatsink, making sure those rectifiers make good contact with the heatsink and retry.

I trust that you had tried it with all the other fuses bar F6 removed, and the F6 fuse still blew? This will isolate the rectifiers from the transformer.

I'm running out of ideas here, but if the F6 fuse blows with all the other fuses out it's looking like a transformer problem or a faulty trace on the rectifier board. Anyone else got any ideas? Anything else now is going to start involving desoldering wires to the transformer.

Do you have a test meter that you can use?

#32 8 years ago

Thanks for input. I have not tested with just the one fuse yet. I'm out of town for a few days and will try when I get back and post the updates.

1 week later
#33 8 years ago

Well I had a tech come by and work on the machine. A lot of money later, it's back up and running. He had to solder some areas on the transformer as well as replace a couple things. Put all new bumpers on the game field and cleaned it as well.

He basically re-soldered all the score displays as they were cracking and caused the displays to flicker. He also re-soldered all the boards in the back board.

Get this, even the wrong size ball was given to me when I bought the game!

I guess I really need to understand what I'm looking for before I buy something like this again.

#34 8 years ago

Mickey0902 thats how you learn
we all had to start someplace welcome to the hobby

#35 8 years ago

Glad to hear that you got it all sorted. Sometimes it's best to call in someone who knows all about the machine and can fix it for you (even though they will charge a lot of money to fix it).

Sounds like it was the transformer terminals shorting out after all.

Good to hear that he gave the machine a good check over, and also sorted out a few developing faults that would have caused you problems in the future.

Now enjoy the game!

#36 8 years ago

Thanks. The only thing now is the lights for the 1st, 2nd, 3rd, and 4th player along with the bottom row lights for instance the "Game Over" don't turn on. They turned on before the game stopped working. I called the tech back and he said he can come by when he is in the area. He lives about an hour away so he can't just drop in.

Do you guys know if this can be an easy fix? Maybe a wire or something?

The center lights are working on the backboard but these specific ones don't. I took the bulbs out of each one and placed in one of the middle sockets and the bulbs work. Is the easiest way to determine the color of the wire and follow it back to where it plugs into the board?

Also, the tech said I will need to eventually replace the top left board because of some corrosion. If one of the chips is moved/turned slightly the game shuts off. He said this will eventually get worse.

Let me know what you guys think. Thanks for the help.

I've attached a picture so you can see the displays at the bottom along with the player numbers.


7 years later
#37 10 months ago

so what the tech say was making the f6 fuse blow upon power up?

#38 10 months ago

I didn't have time to look over this 7 year old thread but if F6 is blowing it's most likely a short in the power cable and/or the line filter and varister.

#39 10 months ago

Some people post a long thread about a repair but then never post the exact result in repair. Completion of a thread is a must to help others who have same issues. If the cord was replaced and varistor is like new then what else?

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