Post by wdln on Feb 12, 2023 20:20:30 GMT
Good day all... I acquired an R-82A a few days ago for the paltry cost of driving 15 miles to get it. Working through the issues... here's what I've done so far:
New batteries in the Memorec
New batteries in the Memory Unit (was surprised to find some here)
Cleaned all pin connectors with deoxit
Re-flowed all pin header solder joints
When I turn on the service switch, the basket spins continuously. Looking at the mechanism control board LED's, I'm seeing "transfer motor" lit, as well as "scan". If I turn off the service switch, I can scan it manually with the scan switch. I can also walk it through a transfer cycle manually with an allen wrench; the transfer mechanism is not bound up and the microswitches are all doing what they're supposed to (side note: the muting circuit and amp is also good, as it will play the record). If I leave it halfway through a cycle and turn the service switch on, it will immediately reject the record and go back to continuous scan, so I know the transfer motor is good.
I have a manual en route... I have not worked on one of these early computerized models where the selection electronics are split between three PC boards (the Memorec, the Memory Unit, and the Selector Logic boards) so it's a bit new to me. It seems like most of that is working though, as I can type in a selection and it appears on the display momentarily before disappearing. However, I can't get anything to appear on the Memorec display, so that could be a problem.
All that said, I think it's possible one of the triacs on the Mechanism Control board is shorted "on". That or the driver feeding it. I had a triac go bad in the mech control board on my R-91 and it would randomly fire the transfer motor when it was just sitting there idle. Ron (rest in peace) helped me find a suitable substitute part... I remember he looked in one of his manuals and the NTE part number was hand-written in the margin.
Anyone from the peanut gallery want to weigh in on a possible diagnosis?
New batteries in the Memorec
New batteries in the Memory Unit (was surprised to find some here)
Cleaned all pin connectors with deoxit
Re-flowed all pin header solder joints
When I turn on the service switch, the basket spins continuously. Looking at the mechanism control board LED's, I'm seeing "transfer motor" lit, as well as "scan". If I turn off the service switch, I can scan it manually with the scan switch. I can also walk it through a transfer cycle manually with an allen wrench; the transfer mechanism is not bound up and the microswitches are all doing what they're supposed to (side note: the muting circuit and amp is also good, as it will play the record). If I leave it halfway through a cycle and turn the service switch on, it will immediately reject the record and go back to continuous scan, so I know the transfer motor is good.
I have a manual en route... I have not worked on one of these early computerized models where the selection electronics are split between three PC boards (the Memorec, the Memory Unit, and the Selector Logic boards) so it's a bit new to me. It seems like most of that is working though, as I can type in a selection and it appears on the display momentarily before disappearing. However, I can't get anything to appear on the Memorec display, so that could be a problem.
All that said, I think it's possible one of the triacs on the Mechanism Control board is shorted "on". That or the driver feeding it. I had a triac go bad in the mech control board on my R-91 and it would randomly fire the transfer motor when it was just sitting there idle. Ron (rest in peace) helped me find a suitable substitute part... I remember he looked in one of his manuals and the NTE part number was hand-written in the margin.
Anyone from the peanut gallery want to weigh in on a possible diagnosis?
