Third button sticks - Rockola 460

Just purchased a Rockola 460 and, after replacing a blown fuse in the credit unit, the third digit sticks.

Reset does reset it
Selections exist.
Doesn't matter what I choose, first push lights up 1st digit button, second push lights up 2nd digit button, then a click, then the 3rd digit stays stuck and nothing happens.

Pushing the scan lever, everything works -- sequencer rotates, turntable spins, etc... No other blown fuses I can find...

Any suggestions?

Thanks in advance!

gr.

Well this is nearly 8 years later and no one answered your post.

HOLY THREAD RESURRECTION, BATMAN!

You're probably wayyyy past this problem but I can recommend two things that might fix an issue like this as I just had a similar problem with my 460. The #8 switch was "sticking."

This is usually either a problem with the switching mechanism (48477-2) which is very unlikely--or the selection board (47486-A.)

In my case it actually turned out to be the whole switch assembly. I purchased a used one from Durfee Coin-op.

I also decided to purchase a spare selection board--just to rebuild one and have it on hand since 99% of selection problems in a Rock-Ola tend to be the aforementioned 47486-A Selection Control PCB.

The only issue with rebuilding the 47486-A is being able to source the proper Thyristor/Silicon Controlled Rectifier (SCR.) All other parts are readily available. For a full list of parts check out page 19 of the manual.

Anyway, the SCR part is listed in the manual only as "47433." 47433 as it turns out, is the GE part number for the SCR. However, GE never published the datasheet so it's damn near impossible to find a suitable cross-reference (xref) part for that thyristor/SCR. HOWEVER, in my 460 the SCRs are NOT GE parts but rather they are IR (International Rectifier) part number IR106A41. This gave me a basis to find suitable replacement SCRs--albeit not in the same panel mount package that were installed on these Rockola PCBs.

Military/High-Rel : N
V(DRM) Max. (V) : 100
I(T) Rated Maximum (A) : 4.0І
@Temp. (шC) (Test Condition) : 30#
I(TSM) Max. (A) : 25
I(GT) Max. (A) : 200m
V(GT) Max.(V) : 800m
I(H) Max. (A) Holding Current : 3.0m
V(T) Max. (V) : 2.8
@I(T) (A) (Test Condition) : 2.5
dv/dt Min. (V/us) : 8.0
t(q) Typ. (s) : 100u
Minimum Operating Temp (шC) : -40
Maximum Operating Temp (шC) : 110х
Package Style : TO-202
Mounting Style : T

Basically, a Thyristor or SCR in this case with a voltage value of 100V or better with the same amperage and specs as above will be suitable. Similar parts are also:

SK6754-5454 RCA
S106A1 HUTSON INDUSTRIES
TIC106A Texas Instruments (TII)
BRX61 TAGS (Tag Semiconductors)
MCR106-3 - On Semiconductor

So long post summary:

1. Clean the contacts on your 47486-A first. Reseat the cables and try again.
2. Troubleshoot which switch is your problem area. Then use page 19 of the Parts Catalog and/or the wiring schematic (sold separately) to determine the problem area. (For example Switch #8 may require replacement of one of the following: S8, D29, D28 and R34, R35 and C14.)
3. If you're certain your 47486-A is working then it's time to examine the switch mechanism itself. This is a delicate piece of equipment when it's apart so don't mess with the copper contacts for the switches if at all possible. In my case, I ended up having to replace mine.

Cheers and happy-fixing, all.

Thanks Madaracs!
I think a lot of people don't respond to old posts because they feel it's no longer relevant. The information doesn't help me with anything I have (currently), but it most certainly will help someone else one day.