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Main => Audio/Jukebox/MP3 Forum => Topic started by: bsabbathfan66 on August 20, 2018, 11:37:25 pm

Title: R-81 Data light solid/Random Selection
Post by: bsabbathfan66 on August 20, 2018, 11:37:25 pm

Hello everyone!

I was looking for some advice regarding my father's R-81 jukebox. He picked it up years back from a friend and never had a chance to fix it. He would love to have it working, and i would like to restore it for him. I have bought the service manual for it, and it seems very informative. Here is the current condition it's in:

- Powers up fine
  - All troubleshooting leds are lit on power supply
- -17V lights up on memory unit
-Magazine rotates and stops at 27 or 77
-"Record playing" lamp doesn't light or display mag position
-Both make selection lamps lare off  (test mode lights them)
-Digits display sometimes when pressed (slightly wiggling wires to selector logic make this go in and out)
-After pressing 3rd digit for selection, "Clock" on memory very briefly lights then goes out.
-"Data" light on memory unit always stays on solid
-And....nothing happens then. No movements. Unless you click reset on memory unit an couple times, then it may randomly select a record and play till its done.
-Unplugging P502 on selector logic makes "clock" faintly light also, along with solid "data" on memory unit.

Thinking about pulling the selector logic and checking for dry joints on connector pins. Am I ok to reflow those as long as I don't touch the ICs? Read they were ESD sensitive I think. My solder station is ESD safe, but i dont eant to mess with anything i dont need to haha. Are shorted wire harnesses common on these? Any other advice or info anyone could share would be amazingly appreciated.

Thanks,

Trenton

Title: Re: R-81 Data light solid/Random Selection
Post by: ami-man on August 21, 2018, 05:36:59 am

Hello Trenton,

It is OK to reflow the header pins on the selector logic, memory unit and the mechanism control, as you say you have to adopt safe handling processers on the memory unit and the selector logic boards.

It is also a good idea to retension the connections in the Molex plugs that go into the boards above.

Regards
Alan

Alan Hood
ami-man
UK

Title: Re: R-81 Data light solid/Random Selection
Post by: bsabbathfan66 on August 21, 2018, 01:10:01 pm

Thanks Ami Man!

Went and pulled the selector logic board. The foam pad that was behind the board literally fell apart into a crumbly mess when I removed it. Can I just replace this with any thin foam to cushion the board? I cleaned and reflowed the header pins for all the connectors. How would you recommend I retension the molex connectors? Is there a special tool needed?

Thanks again

Trenton

Title: Re: R-81 Data light solid/Random Selection
Post by: bsabbathfan66 on August 22, 2018, 10:13:35 am

Well I plugged the selector logic back in after reflowing the header pins and all of my display works great now. Partial success. It did not however fix the data light which is still remaining lit solid. While I was back there by the selector logic, I noticed broken wires to the back lights for "record playing" and "your selection". Resoldered those and lights all work for that now!

I see what you mean about retensioning the molex connectors now. I was able to do that to 2 of the pins, but I am still struggling removing the pins from the connector so it is taking me quite a while for that haha.

Back to the Data light... a lit LED means that voltage is present on the Data line correct? When I unplug P502 from the selector logic (which the data feed is coming from) the light stays lit still.  Have you ever seen the memory unit short the data signal, or do you think I have a wire harness issue?