Rockola 448

Hi
I have this jukebox and it has a selection problem. Firstly i have cleaned the keyboard, plug connections, write in and stop relay, wobble plate slip rings and verified that all fuses are ok. I can only make selections begining woth 1 and ending with zero(100, 110, 120,130, 140,150,160,170,180 and 190). Thoses selections will operate the write in process and read out process. Any other selections will all latch in and lock the tthird button but the write in process doesn't start. Has anyone any ideas what would be causing the problem
regards
seancalla

Hello seancalla

Do you have a service manual? In it, the process is described exactly. See Sequence # 5.

The circuit is not very complicated. The Search Motor starts when the Write In - Relay attracts. The circuit for the start relay is depending on which button is pressed. For keys 0-3, the current flows directly through the key contacts to ground. For Keys 4-7 first the Dual Carriage Relay is turned on. This completes the circuit for the Write In Relay to ground.

Since the selections work with last digit 0, the fault can actually be only in the keypad. The key contacts are connected in series as usual. However, the ground wire goes not (as usual) to key 1, but to the key 0 (to be precise, the link between key 9 and 0). If it is not pressed, the line is further connected to 1 key and so on.

According to your description the connection of the key 0 to key 1 is missing. You write that you have cleaned the keyboard. Did you have it also disassembled? According to the wiring diagram no connection is set. between key 9 and key 0. There may be a contact slide, which does not connect to the next key. If so, this slide would have to be installed on button 9. When it is mounted on key 0, key 1 and all of the following will not work.

Best regards - charly49

Thanks charly49, i didn't dismantle the keyboard but it looks like i will need to in order to do a thorough job, thanks for your explaination and help
regards
seancalla