On my Rockola 460 the #8 switch was either not registering or causing a "stuck/reset" error when pressed out of order.
There are two lamp assemblies (Part 47191-A p.25 of the Parts Cat.) and each of them displays a set of numbers:
1 2 0 1 2 3 4 5 6 7 and 8 9 0 1 2 3 4 5 6 7
Normally when a selection such as "185" is made the following lamps light up: (In Bold Red)
1 2 0 1 2 3 4 5 6 7 and 8 9 0 1 2 3 4 5 6 7
However, in my case the number 8 would never register... UNLESS pressed out of order. That is to say when I selected the number 8 out of the expected sequence it would throw the expected "stuck/reset" error (ie. 8XX or XX8 where X is a valid selection.) So the discreet logic was able to interpret that a button has been pushed but no signal was read when it was used in a normal or valid selection.
Capiche? No matter. I will tell you what I did to fix it anyway.
This selection symptom 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.
Basically it's a 100 Volt 4A Sensitive Gate SCR 3-Pin in a TO202 panel mount package. Datasheet on IR106A41.
Voltage (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
Essentially, 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
Other (unidentified manufacturer) compatible part numbers include:
01H7209, 106A, 107A(SCR), 108A, 134883875401, 1820-0218, 1R10(SCR), 2SF102, 2SF102A, 2SF1099, 2SF1427-100, 2SF357, 2SF522, 2SF941, 3C6100, 3P1MH, 48-83875D01, 48-83875D06, 48D83875D01, 707W00243, 707W00244, 707W00322, 75D01, C106A, C106A1, C106A(SCR), C107A(SCR), C511A, C511F, C511G, C7A4, CR106A1, CR107A1, CR2AM-2, CR3CM-2, CS202-4B-2, CSM3B1, CU12B, CV12B, DRA2B, DRA2TB, ECG5454, F1099, F1099(SCR), F1427-100, F2B(SCR), F941(SCR), IR10, IR106A1, IR106A1-C, IR106A2, IR106A3, IR106A4, IR106A41, IRC10, NTE5454, RCA106A, RCA107A, REN5454, S1004F1, S1004F2, S1004F3, S1004F4, S106A, S106A1, S107A, S107A1, , S108A, S108A1, S108A2, S2060A, S2061A, S2062A, SF1R3B41, SF2B41, SF3B42, SFIR3B41, SK6754, SK6754/5454, T106A1, T106A2, T106A3, T106A4, T107A1, T107A2, T107A3, T107A4, TC106A1, TC106A2, TC106A3, TC106A4, TIC106A, TL106-1, TL107-1, TLS106-1, TLS107-1, TM5454, WEP6242
So here is my long post summary:
If you're having selection problems with a 459, 460, 453 or 455--and maybe others...
Clean the contacts on your 47486-A first. Re-seat the cables and try again.
Troubleshoot and/or identify 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.)
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.
Attached Images
Rockola47486-A-Top.jpg (98.4 KB)