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» Replace which SCR on a Bally -23 lamp driver board?

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Replace which SCR on a Bally -23 lamp driver board?

By jibmums

2 years ago

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Latest reply 2 years ago by jibmums
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#1 2 years ago

DEN

So I was swapping in new bulbs under my Xenon playfield this weekend into those god-awful Bally sockets and most of the dark ones would re-light if I played around with them enough. One just wouldn't light so I hooked up an alligator clip to a good lamp socket's lug to try to check it, touched something on the bad socket that I shouldn't have, and now the good lamp is locked on. Figure I blew out the corresponding SCR on the lamp driver board, but I see that for each lamp there are two SCR's, a 2N5060 and a MCR106-1. All references I've found only say to replace the SCR. Both have replacements available at PBL but which is the one that shorts when something dumb like this happens?

#2 2 years ago

CHD

Cheddar

GoldenStatePin

Lodi, CA

11y 117K 5,180 17 10

OP
Quoted from jibmums:
So I was swapping in new bulbs under my Xenon playfield this weekend into those god-awful Bally sockets and most of the dark ones would re-light if I played around with them enough. One just wouldn't light so I hooked up an alligator clip to a good lamp socket's lug to try to check it, touched something on the bad socket that I shouldn't have, and now the good lamp is locked on. Figure I blew out the corresponding SCR on the lamp driver board, but I see that for each lamp there are two SCR's, a 2N5060 and a MCR106-1. All references I've found only say to replace the SCR. Both have replacements available at PBL but which is the one that shorts when something dumb like this happens?

There's only 1 for each lamp. I don't recall the reason they used 2 types of scrs. They are close together on n the schematic but only a single one for each lamp.
Screenshot_20220207-063528 (resized).png

#3 2 years ago

PIP

Quench

Pinside member

8y 114K 8,025

OP
Quoted from jibmums:
2N5060 and a MCR106-1.

2N5060 are used where it will only drive one lamp.
MCR106 are used to drive one or more lamps (it's capable of higher current). Think of the two Game Over lamps in the head.

OP
Quoted from jibmums:
which is the one that shorts when something dumb like this happens?

Back reference the lamp to the SCR driving it on the lamp driver board schematic.

#4 2 years ago

DEN

jibmums

Pinside member

12y 96,900 3,962 16

Here's the LDB page from the Xenon manual, I see two different types listed -

LDB (resized).jpg

#5 2 years ago

DEN

jibmums

Pinside member

12y 96,900 3,962 16

Quoted from Quench:
2N5060 are used where it will only drive one lamp.
MCR106 are used to drive one or more lamps (it's capable of higher current). Think of the two Game Over lamps in the head.

Back reference the lamp to the SCR driving it on the lamp driver board schematic.

Ah, okay so that explains why the aux lamp driver board only has the MCR106-1's, they each control two of the "chase lamps" on the backbox frame.

So I just need to trace the locked-on bulbs wire to the board to see which SCR it leads to, which I assume will be a, 2N5060 since it's one of the controlled lamps under the playfield.

#6 2 years ago

PIP

Quench

Pinside member

8y 114K 8,025

Which lamp has the problem?

#7 2 years ago

AMR

BigAl56

Pinside+ Frequent

Palatine, IL

7y 64,800 1,655

The lamp driver schematic(s) will show you which SCR to replace.

Just finished rebuilding my Xenon where most of the sockets were toast. It's a pain to replace the original junk sockets that barely survived the factory floor. You may want to consider giving this product a try if you have a lot of sockets to replace. Wish it was available sooner.

https://www.marcospecialties.com/pinball-parts/05-YOP-WW

#8 2 years ago

DEN

jibmums

Pinside member

12y 96,900 3,962 16

Quoted from Quench:
Which lamp has the problem?

2nd blue "N" on the playfield. Here's a pic from the schematics of the shorted lamp, so I just trace backwards from pin 17 on connector J1, which on the actual board looks like it ends at Q13 which is an 2N5060. Not sure if I have that right though, what is the "57" next to it in the schematics?
BLUEn (resized).jpg

#9 2 years ago

237

slochar

Pinside member

7y 86,550 6,882

OP
Quoted from jibmums:
what is the "57" next to it in the schematics?

wire color code see the box at the bottom of that page or other pages

#10 2 years ago

PIP

Quench

Pinside member

8y 114K 8,025

OP
Quoted from jibmums:
it ends at Q13 which is an 2N5060. Not sure if I have that right though

It is the right one according to the schematics:

Xenon_2nd_Blue-N_lamp.png

#11 2 years ago

QUY

FatPanda

Pinside member

7y 141K 7,174 32

FYI, to test if a socket works, you have to ground it. Take a piece of wire and touch the lamp wire on one end, and a ground on the other end. The side rail works fine.

To address a "fiddly" lamp, short of replacing the socket, you can always solder the lamp wire to the "nipple" of the socket. Usually helps in most cases. If it's still fiddly after that, then you'll have to replace the socket.

#12 2 years ago

DEN

jibmums

Pinside member

12y 96,900 3,962 16

Quoted from Quench:
It is the right one according to the schematics:
[quoted image]

Excellent! And now a know I little more about reading schematics too. Hopefully I can get this lamp lighting again. Thanks so much for the help!

Quoted from BigAl56:
The lamp driver schematic(s) will show you which SCR to replace.
Just finished rebuilding my Xenon where most of the sockets were toast. It's a pain to replace the original junk sockets that barely survived the factory floor. You may want to consider giving this product a try if you have a lot of sockets to replace. Wish it was available sooner.
https://www.marcospecialties.com/pinball-parts/05-YOP-WW

I think those are a great idea but I'm actually placing an order today for new bayonet sockets in addition to the above SCR's. Can't decide whether I want to go with 47's, as I love the soft on/soft off look of incandescents, or with colored LED's to give the inserts a color pop, and right now the Yoppsicles are only available in white.

Quoted from slochar:
wire color code see the box at the bottom of that page or other pages

Yep, white/orange, that's the one.

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