Schematic or manual. Figure out what F4 protects. Then dig in. Board issue, bad coil, short to wiring. Once you figure out what F4 does, then at least you have a board or wires to start going through.

LTG : )

Fuse F4 (it's a 5 amp fast blo) controls the coils power. Possibilities could be any of these:

Shorted bridge rectifier BR3 on rectifier board.

Shorted diode on one of the coils.

A burnt coil from being locked on.

Is the 1 amp slo blo fuse next to the flippers also blown?

yes

not yet

did you put your mutimeter on each coil? do any of them not move freely?

Don’t assume. Check them. Can you move them by hand? Don’t replace the connector or pins unless you’re sure they are bad.

first did you do anything specific to the machine between the time it was working and when it started blowing fuses ?

if you unplugged a particular connector, check to see if that connector has the "rejection pin" on it , on the circuit board header pins, one pin is missing and will say "key" on the board.

https://pinwiki.com/wiki/index.php?title=Bally/Stern#The_Importance_of_Keying_Plugs

We all started somewhere. Do you know how to remove the glass so you can lift the playfield?

this fuse is on the bottom the playfield between the flipper coils , check with an ohm meter ... also the F4 fuse check to see if the correct size.

also with machine powered off (unplugged even) manually actuate all the coil driven devices and a visual inspection to see if you notice anything burnt or sluggish

yes very overwhelming at first ....

hmmmmmmm look at the "coin lockout" coil on the coin door as well that would energize when you simply plug the machine back in with the power switch on

Here is a video showing how to lift the playfield on a Bally about two years older than yours.
Starring cfh

A pinball machine on location takes money. If the machine has no power and a coin is inserted it will dump the coin in the coin return slot instead of "stealing your money"

If you are willing to sacrifice some fuses you can try removing some connectors and using the process of elimination try and isolate where the problem is. Since you are new to electronics in the pinball that might not be a bad way to go.

Unplug connectors with a red X through them from driver board and sound board. Power up the and see if the fuse still blows.

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If still blowing remove rectifier board connectors with red x and try again. Leave the sound board and driver board unplugged still
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If the fuse still blows immediately at power up the rectifier board broad Bridge Rectifier #3 (BR3) is most likely shorted. If the fuse stopped blowing when unplugging a certain connector you have narrowed down the issue.

In theory if it was a coil was shorted, sans the knocker and coil lockout, the PF fuse should blow before the rectifier fuse. If the game was working and this happened all of a sudden i'd guess shorted BR3 on the rectifier board.

Are any of the leds in the SOLENOID DIAGNOSTIC leds flashing? This is on the upper right circuit board. If so, what led is flashing?

Is that when the game started blowing fuses ? Meaning after the coin door was opened and closed . If so the wiring from the coin door could have gotten pinched or kinked ,causing a short .

Sounds like the bridge rectifier #3 if only connector J2 plugged in. on the rectifier board

can you solder ? https://www.pinballlife.com/bridge-rectifier-35amp-600volt.html

I believe the problem has been isolated to the bridge rectifier using barakandl 's skilled troubleshooting technique.

he also mentioned the 1A slo-blo fuse under the playfield would have blown first if a shorted diode or coil

The Altek Solenoid Driver Board would also isolate the F4 fuse from a damaged coil or diode on the playfield and give an indication of which coil.
https://allteksystems.com/collections/pinball-replacement-board-products/products/ultimate-solenoid-driver-board

the coil diodes are pre-installed on some new coils for Solid State games and some images show them here https://www.pinballlife.com/flipper-coils.html they are the little black things between the soldering tabs. shown individually here https://www.pinballlife.com/diode-1n4004.html

This means a component on the board will have to be replaced. Pinwiki has great info but if you are brand new to pins you might consider either sending the board out to ChrisHibler or Borygard
https://www.pinwiki.com/wiki/index.php?title=Bally/Stern#-18.2C_Stern_Rectifier_boards
We can walk you through replacing it if you are so inclined and know how to use a soldering iron.

Isn't that board directly soldered to the transformer ? may need a tech to stop by

roughly where do you live ?

They usually have a fin sticking out on one side. Push that in and snap the board off.

Break time.

Youtube has short how to videos.

When I take a picture for here on Pinside. I upload it to my desktop so it's easy to find. Click the attach images tab on this thread. Pick it off desk top to up load it to Pinside. Then write a description if need be.

LTG : )

Don’t give up. To squeeze the plastic pins, you can use a piece of hard 1/8” copper tubing, or a cheap Bic pen with the tip removed. Push down on the plastic piece, then slightly pull up on a corner of the board. Rinse and repeat.

How do the connectors on the rectifier board look? Any burns?

You need to slow down,take a breather and maybe watch some Youtube videos on pinball machines and fixing them. That way you don't make matters worse.
-Mike

-Mike

Pinballlife sells a replacement for rectifier board , comes with the plastic stand offs and new connectors but it will need to be soldered . Pretty sure most replacement rectifier boards need to be soldered .

https://www.pinballlife.com/mm5/merchant.mvc?Screen=PROD&Product_Code=PBL-100-0070-00

You can also get one here

https://nvram.weebly.com/new-pcbs.html

This is similar to the screwdriver I use to get the boards off them pesky standoff tabs. https://www.homedepot.com/p/Husky-8-in-1-Precision-Slotted-and-Philips-Screwdriver-71281H/302735272

Instead of the screwdriver tip in the handle I use the tube of the shaft to push over standoff tit & it works slicker than snot.

Replacements can be found here: https://www.pinballlife.com/search.html?Search=standoff ... looks like the 3/8" ones are for the rectifier board

I have purchased from Pinballlife quite a bit never had to call them though but their telephone number is there.

I have also purchased from member barakandl as well and always had a good experience there.

Did anyone mention that there are 3 screws holding the board in the middle that have to be removed before trying to pull the board off? The replacement boards all go on without the screws because they all use top mounted bridges, so they will float on the spacers.

OP, it sounds like you are completely new to this type of thing - get someone to install the replacement rectifier board for you, hopefully while you can watch and learn. Read up on pinwiki and here for tips on how to maintain and diagnose issues - it seems easy for people here because there's decades of experience here, and there's no shortcuts to getting that experience.

Rectifier J1? That goes to the playfield. Shorted coil likely cause. Without back track reading I thought we went down this road, but can you check all the coils to see if one is burnt/seized/shorted? Check to see if any coils have a shorted diode. DMM on resistance. Lowest ohm setting. Measure across every coil and see if any read 0 resistance (short).

Can you take a picture of this J1 connector so the wire colors are visible?

You have to start learning somewhere.

Youtube is littered with plenty of short how to videos to guide you and help you learn.

Youtube has a search bar. Type in what you are looking for. Like how to post pictures on the internet or forum. How to check a diode. For things like coil and lift playfield. Start your search with "pinball", then how to lift a bally playfield. How to check a coil.

LTG : )

Got posting pics, below the box where you type is a blue box that says attach...

Hit that box, and you can search your computer or whatever you’re posting with for a picture to add to your post.

You have to lift the playfield. Open the coin door, then on the upper right hand side, you will find a spring loaded lever. Move the lever, and holding the lever, lift the lock bar up and out of the way. Slide the glass down. Put the glass on something soft, without banging a corner. You can lean it against a wall or someplace where you won’t trip over it.

Remove the ball(s) from the machine. Grab the front of the apron (side opposite of the coin door) and lift. You may have to pull back on the shooter rod.

Continue to swing the playfield up. Look on the sidewall of the cabinet and you should see a rod that swings up. Insert the free end of the rod into one of the round divots under the bottom of the playfield. This will hold the playfield up.

This is not the preferred long term method - the other option is to slide the playfield back toward the coin door and lean it back on the head. If you’re not sure what I’m talking about, please search utube or whatever to see what I’m talking about. You can easily hurt yourself or the machine if not done properly.

Once the playfield is up, you’re ready to look for the bad coil, diode, wire, etc.

Take your time and watch a few videos before jumping in.

And whenever you are ohming out (checking the resistance) of a coil (or anything else) the game should be off. In this case, the fuse is already blown so theoretically no power, but just as a general rule.

Probably not on the door since the coin lock out coil would be powered by rectifier J2. The knocker too if its in the cabinet for that game.

Do you have a digital multimeter? With game off check resistance, omega symbol on multimeter, across coil lugs and see if any read 0 resistance.

Starting to wonder if the wiring is connected wrong. Go over the wiring to your transformer and rectifier pin by pin.

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