Rockola 442 missing selections

I have a Rockola 442 Jukebox which I have owned for about 15 years. It holds 80 records, designated A1-V8. The entire magazine is filled. When I make a selection, one of three things may happen: 1. The magazine and selector wheel will cycle as they should and the correct record will play and then be replaced in the magazine. 2. The magazine and selector wheel will simply cycle around twice, making no selection at all, and will shut down after returning to the null position. Or 3. Sometimes the letter and number buttons will simply pop back up after the selection is made and the wheel and magazine do not move. I have cleaned all contacts on selector wheel and selection buttons, and have replaced both write in and stop relays with new ones. The problem persists. I have noticed that if the machine fails to play a selection made in a series of other selections, pressing the buttons to the same selection a second time will cause it to play flawlessly. Does anyone have enough knowledge of this machine to suggest steps to fix it? Much Thanks

How/ and what have you used to "clean"-- also "clean" all plugs associated with the write-in circuit. (read above--"how to clean contacts"--)
Ron Rich

Hi
For scenario no 2 do the selection buttons lock in and are they released after the magazine cycles twice, usually if the write in arm is not making full contact and can't make contact it will cycle endlessly
For scenario no 3 the write in relay on the power supply should start the search cycle if the buttons lock in, check that the write in and stop relays are not loose and clean contacts, also clean contacts on the letter and number blade switches at the keyboard, if they are anyway dirty the search motor may not start sometimes. Asle check the connections on the album/singles terminal board beside the keyboard.
I suppose while you are cleaning the contacts of the relays and switch blades you may as well clean the accumulator reset relay and adr relay in the credit unit. Also check for any loose plug connection while you are trying to fault find
Clones

90% alcohol on relay sockets and selector button contacts, very fine emery board on exposed contacts. Also tested solenoids on selector wheel for continuity and function, check out ok.

Just a general question (anybody). Is there something better than either isopropyl alcohol or WD40 out there to clean the small contacts in the selector buttons. I see that in my unit you would have to at least partially disassemble the button enclosure to do it right, and it appears there are a great many small parts in there that could get fouled up. If I can do a decent job of cleaning without disassembly, it would be preferable. In the past I have used alcohol or WD40 (and of course throwing protective cloths over both mechanism and records when using the latter), But then again, I may be barking up the wrong tree. The selector buttons DO always choose the right record (when they do it at all.)

Clones, the search motor always engages as soon as both letter and # buttons are locked in. I have no problem with that. The only exception is when it "finds" no tripped pin. I think something is causing a pin not to trip on occasion. I have also made like five selections, and the mechanism will seem to cycle normally to play maybe 2 of them and then shuts down. It is as if the other three were never selected, although of course they were.

Hi
I wouldn't clean the selection buttons with alcohol or wd40, the best method is to remove keyboard and clean with an ammonia solution followed by several rinses and thorough drying. At times the selection buttons will start the write in process but they wouldn't be making a 100 percnt contact on order to pick the selection so cleaning is required. The pulse to move the pin comes via the accumaltor reset and adr relay in the credit unit so it wouldn't do any harm to clean these. Also check to make sure the copper u shaped spring at the wobble plate solenoid is in position. If I understand you correctly when you make a selection and it doesn't work the write in units cycles endlessly or a few times?
clones

I would suggest that WD-40, be discharged to the trash can--I never us it anywhere near a coin operated phono ! The same goes for anything that contains any "sandpaper". My recommendations for contacts on something like a switch, or relay, are posted above, in the "stickies". For contacts that ride a "slip-ring", or rivets, I use Deoxit 5, exactly as per the instructions on the can.
Since it is always the 1st selection, is the "helper spring" good on the wobble plate coil ? Ron Rich

Thank you for the advice, Ron Rich and Clones. I will keep you posted on progress.