The schematic should help identify the fuse values. Based on the pic you posted, I'm thinking the middle one is possibly it. Lamps are usually 6v. Do you have a multimeter? As a start, I'd pull the 6v fuse and check it for continuity. Fuses can look good, but actually be blown. On a schematic, fuses usually are signified by a wavy line between 2 points.

Edit: looks like values are right on the label next to the fuses. Make sure *all* fuses are the correct values while you're at it. The value of the fuse should be engraved on one of the fuses caps.

The 32 volt fuse rating is fine; it represents the max working voltage of the fuse. The current rating is the critical value, and yours was fine. It was probably cooked by an intermittent short.

The other fuses are 10 and 15 amp rating. "ACG" is the Bussman designation for a 1/4" x 1 1/4" glass tube fast-blo fuse; I believe 32v is the standard voltage rating for this type. The number represents the current rating, so you have 10 and 15 amp values (but I think they were reversed, and the one in the 50v circuit was probably under spec'ed if it is a standard 32v ACG type).

(Edit because I didn't see at first that your blown fuse is a slo-blo - the coiled fuse element identifies this.). The best approach is to see if the schematics specifiy which type, otherwise stick with slo-blo. Slo-blo fuses delay blowing by a slight amount in order to accommodate the brief current spikes which are inherent in some types of circuits such as switching on coils. A fast-blo fuse replacing a slo-blo will not cause any harm but can nuisance blow during normal operation. On the other hand, a slo-blo should never be substituted for a fast-blo, as the delay in melting can cause circuit damage.

Those are common values, but you will probably need to go to a hardware or electrical supply store to find slo-blo types as well as ones with sufficient voltage ratings for the 50v circuit.

You want slow blow fuse. The middle fuse (which looks blown) is a wire coiled up around a tube inside the glass fuse, those are a slow blowing type.

The voltage rating is a maximum type rating. Ie a 32v fuse should only be used in a circuit up to 32v. Most glass cartridge fuses now-a-days are 250v rated, well within you 6v lamp range.

Home improvement type stores might have the fuses. We have Menards around here and they carry a good selection of fuses including the one you need.

Note also that the designation for fast or slow blow is often AGC (fast blow) or MDL (slow blow). To illustrate, here i have a box of 3 amp slow blow (aka MDL) and a box of 10-amp fast blow(aka AGC). In the next pic, you'll see the slow blow fuse on the left, fast blow on the right. Note the "beefier" filament in the slow blow fuse, while the fast blow has a thin strip instead.

IMAG3107.jpg

tmp_12899-IMAG3108338333072.jpg

Bingo-you can go higher on voltage, but *not with amps*

Edit: you can also try hardware stores for fuses, maybe try calling around? If you lived closer I'd give you the fuses, i bought a ton from a local RadioShack before they closed.

It might be a slow blow in there, but every EM I have worked on uses fast blow for lamps. Slow blows are general used on bank reset coils mounted under the playfield.

You can safely use a fast blow in place of a slow blow, it just might not survive surge situations.

Considering how the lamps work and comments from posters above, fast blow probably will be fine here.

If that one bulb is all you messed with, i'd check for a short inside that light socket. Those old bulb holders can get pretty crusty with age. Sometimes something gets inside the socket and can short it out too.

Looking at your top photo, (bulb holder on the right) you may want to check that the tab to which the wire is connected is not touching the bulb holder housing (Looks that it is very close in the photo).
You could also disconnect the wire to the holder and power up machine to see if it is the problem.

Good news !

I am not as familiar with Bally EM titles, I'm more a Gottlieb EM fan. From what I can see on the IPDB site, there are x 2 other stepper units in the backbox apart from the credit unit. I am confident that one of those units will control the 'Ball in Play' lighting. I would check that the contacts on the rotating disc/s are clean and making good contact.

Coincidentally my Bally Rocket III of same era started doing similar yesterday. Per the post above, investigate the bulb holder itself and spider/circuit board on the "Ball Count" unit. This is my first EM and I like the way everything is conveniently labelled. Here's the Ball Count unit on mine. This game can be configured for up to 7 Balls so steps 7 units on one lever and total resets back to 0 on the other and the fingers on the spider complete the circuit to the relevant ball-in-play lamp.

20170411_122043 (resized).jpg

Match unit doesn't need to reset so single coil and no return spring is correct.

Use an old shooter rod rubber