Bally Centaur - Many Bulbs Out (Solved!)

Assuming you have no lamp driver board issues install new sockets. Bally's from that era have crap sockets.

Also, the lamps do not work like Williams, there is no matrix. One buss feeds all the controlled lamps and then a single wire controls each individual lamp. GI is the same as Williams.

Pinball Life has them.

Are the sockets the wedge type? Can't remember when they changed from the bayonet style.

Centaur is 555s everywhere.. and apparently the sockets are extremely hard to find, for whatever reason.

I've never had any issues with my Centaur lamps EXCEPT the pop bumpers. After about 3 games both pop bumper lamps would go out. I did put the older style red Coin Taker 4+1HP LED lamps in each. I'm not an LED guy, but this was my only option. Not had an issue anywhere else.

Might want to try re-seating the connectors on the lamp driver board. If they magically relight after doing this, probably best to look at replacing headers and connectors. Those .100" headers and connectors are crap.

Those wedge base lamp sockets Bally used were all crap. They'd lose the connection at their spot welds.

I would always replace them with a brand new bayonet base socket from Pinball Resource.

You can sometimes get more life out of those crummy 555 base sockets by using a pokey tool and squeezing together the contracts. This adds more tension.

Also, the feature lamps work like this. What you refer to as the ground wire is actually the wire that is hot. All the feature lamps always has 6.3 vdc on them. The lamp driver board, through an SCR, gives a feature lamp a path to ground to complete the circuit and light up the bulb.

Knowing this you can manually apply ground to the lamp socket (the leg with the color coded wire) and see if the lamp lights up. Doing this will test the bulb and socket.

Id say you either have a socket problem and/or a board prob. It is probably both. Id put in an Alltek lamp driver board and see where your at. Plus you can switch to leds as desired. Whatever doesnt work then, is most likely socket oriented. Change those sockets out to the newer 555 style. Sometimes you can bend the wire leads in half to make the bulb thicker to make contact with the socket. Also, with power off, a small flat tip screwdriver can bend the clips in the socket closer together to make contact with the bulb. Most likely some of the sockets will need to be changed.

For what its worth you don't really need to worry about those breaking from bending them back and forth.

It could be the crappy sockets but most likely you have some bad scr's on your lamp driver board or aux lamp driver board. I had to replace a bunch of these on my Flash Gordon and a few on my Centaur II. I believe they're a 2n5060

The smaller SCRs are 2n5060, 2n5064, or MCR100 are all fine replacements

The larger SCRs that can control up to 2 lamps at once are MCR106, C106, and more acceptable part numbers i can't think of off top my head.

I repair these lamp boards. $30 shipped back with new connector pins and every lamp circuit tested/repaired.