Rock-ola 424 Issue - Selector pin not resetting intermittently

[Spinal Injury]

Ok, I will describe what I *have* done already in order to fix this
issue. Using the service manual "Sequence 7 - Selection Lever Reset"
page, we see power going through the play control relay, then #2
Micro, through the A/B snap switches, along to the wobble disc circuit
tracings and the reset solenoids on the read-out arm, to the interlock
relay trip contacts, back to ground. I have cleaned the snap switch
contacts, the interlock relay contacts, the outer part of the wobble
disc, pulled the read-out assembly, tested the solenoids (they work
fine, not sticking), cleaned all the wiper pins, and the 2 contacts
which are held in by thin springy pieces of metal. The interlock
relays seem to function as designed. All this has been fully cleaned,
yet I still have intermittent issues. Sometimes the solenoids pull in
nice, resetting the pin. Sometimes I see the arm attached to the
solenoid 'twitch' - like it's getting partial power. Sometimes I see
nothing at all. This happens on both the inner and outer ring of
selectors. I have not touched the play control relay as of yet, or
examined micro#2. Any other paths I may to explore?
Thanks - S

[Spinal Injury]

Concentrating on the #2 micro, which seemed like the most likely
culprit, I see all three of those micros look sealed - so I took a
chance in that they were not totally sealed. I had a can of Deoxit F5,
for faders - volume controls, pots, etc, that I use for old radios,
guitar amps, what have you. I sprayed a bit on the tops of all 3 micro
switches, not really thinking this would actually do anything, but
don't you know, I had 3 good resets in a row after I did that. Before
jumping for joy, I did a little more spraying, let it sit for half a
day, then ran the thing through all 100 selections. Every single one
reset the selector - not one time did it fail. I was thrilled! I do
wish there is a way to open up those switches to really get in there
for a thorough cleaning. If anyone has ideas, please pass them along!
Meantime, I am going to rebuild the electronics. All those
electrolytic caps need to go. The big ones on the outside I will
re-stuff with modern components, just like I do with old radios - keep
it lookiing 'stock'.

S

On Wed, 05 Jul 2023 20:30:52 -0400, Spinal Injury

Post by Spinal Injury
Ok, I will describe what I *have* done already in order to fix this
issue. Using the service manual "Sequence 7 - Selection Lever Reset"
page, we see power going through the play control relay, then #2
Micro, through the A/B snap switches, along to the wobble disc circuit
tracings and the reset solenoids on the read-out arm, to the interlock
relay trip contacts, back to ground. I have cleaned the snap switch
contacts, the interlock relay contacts, the outer part of the wobble
disc, pulled the read-out assembly, tested the solenoids (they work
fine, not sticking), cleaned all the wiper pins, and the 2 contacts
which are held in by thin springy pieces of metal. The interlock
relays seem to function as designed. All this has been fully cleaned,
yet I still have intermittent issues. Sometimes the solenoids pull in
nice, resetting the pin. Sometimes I see the arm attached to the
solenoid 'twitch' - like it's getting partial power. Sometimes I see
nothing at all. This happens on both the inner and outer ring of
selectors. I have not touched the play control relay as of yet, or
examined micro#2. Any other paths I may to explore?
Thanks - S