Rock-Ola 481 No Display, Dead

[rockolarick]

Hello, I have a 481 and the record display, the credit display, and the buttons are all not working and not lit up.  I am unable to make a selection.  I can, however, press the test button on the logic board and it will go through the test sequence of playing the records.  I read the sticky about adding a new battery outside of the Hit Tracker and cleaned the edge connectors, which I did.  Looking at the wiring diagram, I do have voltage to all of the 3 above.  Can anybody help me to what to look at next?  Thank you so much.

*** I did see a suggestion of swapping out the display controller (driver) in the Hit Tracker with the Profit Setter and they both worked, so problem still exists.

Rock-Ola Rick

[jukenorman]

I think that sticky about the battery applies to the 490 and later models. So you said you have voltage, have you got 9.6VDC - measure it at the pink wire on the plug from the power supply to chassis. Can you also let us know whether the jukebox was operational and your fault has just occurred ie the history?

Norman.

[rockolarick]

Hi Norman, Thank you for the reply. Yes, I do have 9.6 VDC at the pink wire. I got this box a few months ago and when I first plugged it in the display was working. I can't remember if the selection buttons were working or not because the gripper motor was seized, which I have since fixed. All of a sudden the display stopped working, so I jiggled the wire connectors at the profit setter and the display would flicker on and off. Not long after that it went out and can't get it lit back up.

[jukenorman]

On the basis of your last post, I suggest that you go over the solder joints (in the profit setter) for the connectors and interconnectors. There are a couple of versions of profit setter (interchangeable) and the earlier one has two circuit boards that plug together (if I remember correctly), I don't remember if the later one is the same. These jukeboxes are notorious for bad solder joints - if I get a dodgy amplifier, the solder joints are the first thing I look at.

Norman.

[rockolarick]

Thanks Norman. My PS has only one board as it does not have the two circuit boards. I tried taking off the PS board, looked at the solder joints and they all looked good. I took off the pin connectors and sprayed contact cleaner on both the pins and the sockets. I also took out all of the IC's cleaned them and sprayed contact cleaner inside where the pins go. Unfortunately, I still get a blank display screen. Any other suggestions I can try?

[jukenorman]

There's very little to go on here tbh! I think I would have been inclined to redo the solder on the connectors despite them "looking good" simply because it requires little effort and it is an established common fault! Of course we don't know whether the lack of display is down to the profit setter or the digital display board itself so that is also something to investigate.

In your first post you said this "I did see a suggestion of swapping out the display controller (driver) in the Hit Tracker with the Profit Setter and they both worked, so problem still exists". What exactly did you mean - do both display drivers work in the hit tracker?

You also said that jiggling connectors previously reinstated the display so I do think it's worth pursuing that line first of all.


Norman.

[rockolarick]

When I said they look good, I meant I tested continuity from each pin to the next solder joint that pin was on. Not sure if that's a good test or not.

Correct, all 3 display drivers worked in the hit tracker, so assuming the one I put back on the profit setter is ok.

I did measure 9.6v on the pink wire on the connection into the PS. I did however follow that 9.6v path and tested a few IC pins and also tested the pink wire at the credit display and the record display. The IC pins got me around 8.6v and the two displays got me around 8.4v. Is this normal or do I need to see 9.6v throughout the profit setter? Is this a capacitor issue on the PS? Thanks!

[jukenorman]

I'm not sure at all about your test but what I would say is that on a machine where poor solder joints are a known issue, you would have been as quick to reflow solder on the connectors as to test them!

So where does that leave you - with your "worst nightmare" I would say, and it's for these situations that I keep a spare working profit setter.

All I can suggest is that you follow the schem-a-grams in the manual. Make sure the profit setter is not set to free play (otherwise the credit will ramp up to 99) and reset it. Start at the beginning, insert the coin (ie operate that input) and using a logic probe and/or multimeter, follow the shem-a-gram circuits through to the point where "1" is displayed in the credit window. If you successfully get that far, you can then use the add and subtract credits to ramp the display up and down. Download the data sheet for the display driver so you can see what outputs you should be getting. By doing that or a variation of it, you might be able to determine where the problem lies.

Let us know how you get on!


Norman.

[rockolarick]

ok so update. After replacing the Decoder and Controller ICs, I was finally able to get display. When the basket turns I am able to see the display cycle through the record numbers. Also, I am able to add credits and subtract credits, but I am still unable to make a selection and have the numbers show on the display. Also, when I put coins in or move the coin levers, nothing happens. When I look at the manual on selecting the first number and inserting coins, I think the IC702 (credit rom MM5781/NCY) chip isn't working. This part is very hard to find online. Any other good ideas I can try that i'm not thinking of? Thanks

[jukenorman]

I'm not saying you're wrong about IC702, but I am extremely dubious! If the add and subtract buttons are working, that generally shows that the profit setter is basically functional. These buttons are internal to the profit setter whereas the others are external and they are all using the same comms lines on a switch matrix. There is another thread not very long ago covering a similar issue and fault finding the pushbuttons - check it out.

jukeboxaddicts.proboards.com/thread/4411/rock-ola-display-write-issues

Norman.

[rockolarick]

Just an update on my progress. I was lucky enough to find a used profit setter for a really good deal, so I swapped it yesterday and everything works perfect! I verified it wasn't any of the IC chips. I am still curious to try to find out what is wrong with the PS. If the PS wasn't recognizing any coins AND not able to make any selections AND all of the IC chips are ok, what else could it be? Looking at the manual both of these actions (inserting quarter and pushing the 1st button) go through the K1 line. Do you think that is the issue?

[jukenorman]

I would suspect poor solder joints, like was mentioned early in the thread - especially since you've found all the chips yo be OK.

Norman.