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 with 1 and ending with zero(100, 110, 120,130, 140,150,160,170,180 and 190). Those selections will operate the write in relay, the write in process and read out process. Any other selections will all latch in and lock the third button but the write in process doesn't start nor does the write in relay energise. Has anyone any ideas what would be causing the problem
regards

Clones,
Just a guess--an open in the keyboard circuit--a "premium price" setting, set wrong ?
Ron Rich

thanks Ron, will update if i get any progress

Hi
Just can't figure this one out, the pricing jumpers are at standard, can't find any shorts in the keyboard, its strange the way it will select anything ending in zero and will not select anything else, just as a further note, relay K7 does not energise on selections ending from numbers 4 to 9 which it should and this then should activate write in relat K3. All other selections ending in 0,1,2, and 3 operate relay K3 directly. The rerlay is energising with selections ending in zero, for all other ones there's nothing. The first digit and second digit lights come on as normal and the reset light comes if a wrong number is entered. Also just to note that when a selection other than the workings ones is made, the reset key will release the buttons
regards
clones

Clones,
By any chance, does this model use the approx. 6 inch x 6 inch small selection board, with the two multi pin plugs, slid onto two opposite ends ?? If so, are these plugs black in colour ?
Ron Rich

Hi
Yes it uses the selection board, plugs are white on mine
regards
clones

Clones,
OK--the white plugs depending on the brand that they used on the day it was built, were overall MUCH better then the black ones--however, if A-MP brand they tended not to retain the tension on the individual pins. If Molex brand, they tended to be better at this the the A-Mp ones, but sill, once in awhile, need to be "reformed". Also check that board VERY carefully--it tended to develop "hairline cracks"--cold/dry solder connections. I strongly suspect the problem is related to that board. Other parts failures are also common on that board--Ron Rich

ok thanks, will investigate and revert back, never had really many problems with keyboard/selection assemblies, its a pity i sold two fairly cheap about a year ago, just goes to show never get rid of anything, might put a request in the wanted section
regards
clones

Hi
I checked the board and can't see any hairline cracks or cold/dry solder joints on the board, i tried another board i have , but no luck with that. Can anything be done to improve the connectors or is it a case of replacing them
I still can't get my head around why it will select the selections ending in zero and nothing else, previous issues with keyboards would be either intermittent selection or none at all
clones

Which brand connectors do you have ?? Ron Rich

Its an AMP type, i tried some of the higher selections ending between 4 and 9, whereby relay K7 and operate K3 to start the write in process, i actuated it by hand and the write in process started, i suppose this rules out any issues in the power supply, according to the manual circuit runs from latch through the push button and to relay K7 and there on to write in relay K3 and for the other number ending in 0,1,2 and 3 the circuit goes directly to the write in relay K3
clones

Hi Clones,
Since they are the white, coloured, A-MP brand plugs, I can not recall if it is possible to remove individual contacts from that plug--if so, I suggest that you do so, and "reform them" to add tension. I usually just replace both of them with the Molex brand item.
I agree with your assessment that the power supply is not the problem here--
If the "plug repair" above fails to correct the problem, you will just need to figure out what else is "common" to those circuits, using the schematic--Ron Rich

Ron
I seem to have found the problem and purely by accident, i should have known it would be the keyboard and bad contacts, this might sound a bit confusing on line but here goes- looking at the keyboard today i entered a selection, and by applying slight pressure on the keyboard wafer at one end the selection (where 0 is located) the selection went ahead and was consistent with other selections made after that, so there has to be intermittent and bad contacts, it now needs to be dismantled and washed and cleaned with ammonia solution and rinsed, you have mentioned this method before for cleaning keyboards, any idea on the strength or concentration of the ammonia solution
regards
clones

Hi Clones,
I just "borrow" some of my wife's household ammonia--but remember--I have no sense of smell !
Do it out doors--on a hot, sunny day ! Ron Rich

Thanks for your help Ron, i am running out of hot sunny days in Ireland, some years they are a rarity
regards
clones