Rock-ola 477 Max random play, no play, etc.

[prime]

Hi my jukebox has run well since i got it to operate about 7 years ago, 3 weeks ago it did something strange, it returned the carriage to the finished position, then the gripper activated and went through its motions starting the turntable with nothing on it, when i canceled it did it again. I removed power from the unit and restarted it, all went back to usual. When i purchase this unit i noticed it was already set for 99 free plays. Now i find the unit will grab a record randomly and will just keep playing it over and over, if i try the scan switch it will sometimes do nothing then all of a sudden work again, Also now i can only make a selection after it has been turned off and on and that selection does not engage any mechanism, after screen is blank unless i turn the unit off and on.  

[prime]

Ive spent more time with the unit and i hope someone can help direct me, i know the first thing to check is the 9.6 dcv , the service manual states to test pink wire and ground at low voltage, on the profit setter there is a connector with 6-8 wires connected, on mine none are pink. Is the pink wire under the protective cover? secondly i find when i turn on the unit the scan will not work but if i wait 2 minutes it will engage at the same time the gripper engages with no record selected and without the magazine moving, if i cancel the record it will return spin the magazine and stop, now scan is inoperative for another few minutes.

[prime]

Ok im a little slow but found the low voltage power supply and i have 9.577 DCV at pink wires.

[jukenorman]

Hi Pete,
There should be test procedures you can run through for the various moduless which are in the manual. These particular jukeboxes can be prone to poor connections / bad solder joints - as a sweeping generalisation!

Norman.

[Ron Rich]

Pete,
My GUESS would be either, like Norman mentioned-poor connections/solder joints, OR, "flat caps" in the power supply/selection, sections ? Ron Rich

[prime]

Ive looked at connectors and they do seem sound, when i used to turn on the unit it would cycle and show different numbers on the display, now nothing happens when you turn it on, after turning on scan will work once, if you wait 2-4 minutes with power on scan will work again once. when you turn unit on you can use buttons to select a song, numbers selected show on screen but nothing happens, if you try numbers again nothing just blank, at this point if you push red clear button on profit setter you can reselect but nothing moves. I am going to try all of the tests listed in my manual but nothing describes my issue, maybe my manual is missing some pages. Ron when you mention power supply/selection section which board is this, i cant find anything in my manual listing this. pete

[jukenorman]

Hi Pete,
The original Rock-Ola manuals came with a seperate large fold out schematic which would have covered all sections including the power supply. You can get repro copies of this schematic, I know that jukebox-world.de sells them.

Norman.

[prime]

Ive been looking at my manual and it has a logic board test, it states the quickest way to test the board is to press the test button and then the unit will select programed selections 100-194-197-200-294-297. when i pressed nothing happens, does this confirm its the logic board?

[jukenorman]

The manual says that if this happens, the problem area is A-B Snap Switch, Opto Board, or Logic Board. In light of the fact that you've said "when I used to turn on the unit it would cycle and show different numbers on the display, now nothing", I might be inclined to start with the opto board!

Norman.

[prime]

I checked to Opto board, all wires are secure and i dont see any broken solder joints, i used the scan and watched the A/B switch and unit stopped at indentation on wheel. Ive noticed that the now playing window shows a record playing when none are on the turntable and magazine is in idle position. I can clear now playing with profit setter clear button. pete

[Ron Rich]

Pete,
How are you "checking" things --like the connectors-- and the opto itself ? Which type "connectors" were used on the boards ? Ron Rich

[prime]

Im looking at a few facets, first checking to see if the light on the OPTO board flickers when the magazine spins (yes), secondly unplugging the five wire connector and making sure all wires are intact, i checked the solder on the rear of the board to see if there was any damage or cracks. every time i turn the unit back on i can use the scan to start magazine then putting the scan to operate makes the magazine spin to the idle position. Should i remove the opto board to check the face . I noticed the 99 free play light was not on and if i hold a little pressure on the connector it lights up, i will investigate that poor connection.

[prime]

On the display unit is a harness on the left side below the free play, from what i can see someone in the past has added two wires to jump one pin back on two of the pins, I cannot keep the 99 play light on, can do these pins affect selector, if so i may need to replace the board because i dont know why it was jumped pete

[prime]

I removed the OPTO board and i get resistance from all resistors except R502, it may be so low my multi meter cant detect it. all capacitors and transistor seems to be ok.

[jukenorman]

R502 should be 27K ohms.

Norman.