R87 (Golden) Woe

[petert]

Hi there, newbie from Cumbria here. Hope you don't mind me interloping for a while.

Whilst visiting a friend, I noticed he had a jukebox in the corner of his garage. It seems it was installed in a pub he visited frequently in his youth and when the place was gutted for conversion into a dwelling he "came by" it along with about 300 or so singles of the 60s 70s and 80s. The sweet spot of our youth.

He'd had it for about ten years and it was probably unused in the pub for about 5 before that. and he was just waiting to summon the enthusiasm to get it fixed.  It switched on, lights on, static hum over the speakers but no LED display or response to input.

I have some enthusiasm for the electromechanical so I downloaded the service manual and opened the bonnet.

First thing I noticed was that it has a Rainbow amplifier unlike the one in the manual. Is this common and/or acceptable?

Second thing (working through the trouble shooting chart now) PSU showing all three LEDs and 8v LED showing on the Central Control Computer so there is power getting in. My instinct is to clean up all the connections first and check for loom continuity.

Is there a standard procedure for dealing with these multi pinned plugs, looks like there's a bit of verdigris particularly in P-105. I'm thinking that it'd be easier to take the back off the CCC to better access the pins and work into them with switch cleaner on a cotton bud. What is best practice for cleaning the sockets? Do the contact sleeves slide out smoothly and easily with the correct technique/tool.

Any advice would be welcome, id love to see it running for him.

Going to pore over the wiring diagram and chug on a beer for an while 

Best Wishes
Peter T 

[Ron Rich]

Hi Peter,
My advise-- READ the Service Manual-- and READ the "Hi Newbies" post here. There are also "stickies" at the top of this post that should be read, and acted upon, prior to powering up that phono again !
Ron Rich

[wdln]

In addition to the connector issues Ron refers to in the stickies, I've had a number of jukes with very dirty service switches, which is also referenced in that same post. This is the 3-position slide switch off to the left side that lets you change between operating mode (on), load-record mode (service) and "kill everything" mode (off). Those contacts need to be cleaned and exercised so they're making good contact in each position. Repeat this clean-and-exercise cycle several times with the power off using a contact cleaner like Deoxit. If that switch is not completing the circuits properly in operating mode (it's a multi-pole switch), the juke will appear to be dead.

I've also found cracked solder joints on the CCC and other boards where those multi-pin connectors press on.  Carefully heating them up and adding a tiny bit of new solder can usually bring them back around.  When you pull the CCC, you're likely to find a piece of foam backing that is/has already turned to powder.  Clean all that off with a toothbrush.  To replace it I've cut out pieces of that soft styrofoam sheeting that is used to wrap fragile stuff for shipping.  A couple layers seems to be about right.

The battery on the system board may also be dead, which can cause a DOA appearance. If the battery is missing or completely dead, it's beyond just forgetting your settings when you power it off. It will put garbage into the music queue on power-up, not accept valid selections, or just act dead and not work at all.

You've got the book, which is a great start. For sure the connectors and service switch will need to be cleaned and possibly adjusted/resoldered so they're making good contact. The system battery on the CPU board will almost certainly need to be addressed.  Make sure you know the specs before swapping it... some need to be rechargeable, some are just a plain button cell. Once you do those things, follow the troubleshooting chart in the book for remaining symptoms and start working your way through the solutions.

[petert]

Thanks for the pointers Ron, I will endeavour to comply with board protocol. I'd already read the manual front to back and have now read all stickies. Found your post on connectors very useful, and, of course you highlighted the potential problem with the service switch.

Thank you also for your response Dave L. From what I'm gathering from my initial browsing here, the switches need sensitive cleaning beyond what I've experienced in auto and more up to date audio electronics (that is to say, I've cured many a crackly volume pot and kept Italian motorcycle looms running in UK weather) I now have a can of Deoxit on order which may well be less intrusive that the contact cleaner I've used for a while. I'll give the service switch a go when it arrives. Nice pointer about the Styrofoam sheeting. I'll keep some on hand when I open the CCC. I'll keep an eye out for a battery too.

Edit: Whilst looking for images of the component side of the controller PCB I came across this image identifying a battery

images.app.goo.gl/gj3xCi5SXATrAgiX6

which would make sense as the verdigris on the 105 connector is directly below this area. Am I on the right lines here?

Won't get to look inside for myself until midweek now.

Thanks again for your comments.

PT

[stingman]

Go to abjukeboxrepair.com and sort through the many how-to videos by Bruce Wentworth.

One of the videos shows exactly what you are looking for.

Your R87 is right in the wheelhouse of the repairs shown on this website.

Their specialty is R84-R94 Rowe AMI jukes and CD players.

[wdln]

Yes Peter, that is the system board battery, that weird black metal box that says DataSentry in that photo.  It is rechargeable and I don't think you can get those exact units anymore.  I actually just went through all this on my own R-88 recently, as I was looking for something that looked like a button cell or stack of button cells (all the text had faded away on the factory battery).  What I ended up doing was putting two NiCad AA batteries in a plastic holder stuck to the wall near the CCC.  I wired them into the CCC circuit board via an inline connector, just to make removing the CCC easier in the future.  You could also use NiMH batteries, and AAA's would also give plenty of power vs AA's.  I used AA NiCads because I had some lying around.

If you do warm up those connectors on the CCC or any of the other boards, take your time and be careful so you don't accidentally short two adjacent ones together.  Make sure you check/clean the connections on all the boards: the CCC, the pricing board, the mech control board, and the selector button board.  If you find that one number button doesn't work, it's likely the connections between those boards and not the button itself.

If the service switch is really sketchy, it may need to be replaced.  I had the one on my R-88 cleaned and working just fine, but it has started flaking out again on power-up.

[petert]

This is all great info. I'll check out some YouTube and report back when I've had a go with the new switch cleaner.

[Ron Rich]

Guyz,
You can use almost any 3.0 or larger Ni Cad, to replace that Battery. Or, you can replace the main "chip" with the CD Adaptor product, and eliminate almost all problems related to the CCC, and the battery ( a great product !!).
The service switch must be removed -- totally "cleaned" of any "residue", with either a "safety solvent", or rubbing al-key-haul, then re-cleaned with Deoxit -5, following the directions on the can-- won't fail again for many years, if done that way --
"--Warm up connectors--" ? Are you speaking of the soldered headers ? If so, see the above "--common problems" sticky.Ron Rich

[petert]

As I was searching for images of the CCC circuit board I noticed that a few had different components in that location, there was one which looked like a pack of yellow NiCads. It'll be interesting to see what's in there in the light of what I'm assuming is a non standard amplifier. I've some experience in working on 1/10" circuit boards and vero boards so I'm fairly confident that I can resolve an odd dry joint (do you call them cold joints in the US?) I'll post some pics when I get in there.

[wdln]

We (or at least I) call them cold joints! I guess I think of it as not enough heat was applied to the components to make the solder "take" to them. But in the case of a cracked joint, mechanical stress is the issue.

[petert]

I did some roady work over there in the 80s and had to learn a new language fairly quickly. I guess we call them dry joints because the wet solder never actually connected. And when I say solder, I pronounce the letter L 

[jukenorman]

The major UK operator (MHG I think) of the time imported these machines from AMi without amps and then commissioned their own, hence the Rainbow amp.. The perceived wisdom is that these amps are only worth spending minimum time on - and then look for an original replacement.

Norman.

[Ron Rich]

Hi Peter,
Usually called "cold sod-der joints" here -- no "L" sound as you pointed out ! I have been siting here attempting to insert the L sound to no avail-- just "twists up" my tongue --- Ron Rich

[wdln]

Huh. Was that somehow easier than the minimal changes needed to convert the amp's power supply over to 220V?

[Ron Rich]

Hi Dave,
Probably done to circumvent some customs charge-- did not "import a phonograph", only "parts" to build one ! LOL ! I have seen operators purchase new Seeburgs, toss mud and all kinds of "dirt" in/around them, just to fool the customs inspector, into thinking it's an old unit ( also would remove, or change the total play meters to show many plays---). Ron Rich