Some things are Done and just lasted as long as they did. You did more then any manufacture would. As they just would scrap it as a loss. You're a great teck!
A friend of mine says that when you throw away "Black face" receivers, you should place them vertically so that you can fit more of them into the barrel.
I absolutely liked it. Amazing the amount of diagnostic you did on this. It was bugging you. I have one of these units in great condition appearance wise, but it will not output speaker level sound. Renders it useless other than maybe some kind of pass through unit that also isn't worth it because of its size.
Did you try the initialization process? PG 13 of service manual. Turn off, remove AC, hold A and B, plug in, entire display flashes at 1hz, release buttons. Just in case something in the code has got mixed up. Stranger things have happened :)
@norcal715 You can be considering the reprogram action of the processor. In this case you can procure the new PROM the software and the device to reprogram it. For this specific model I've investigate with a people that fix it. The problem is to procure the code for coping into the PROM
When you said you get different results each time you click that button makes me think of a TV I once had that didn't have a remote and sometimes when I would turn up the sound the channel would change and when I would change the channel the menu would pop up, or the TV would shut off. The replacement of the tact switches solved the problem. Maybe the tact switches on this unit are bad.
Maybe try replacing relay A+B and check transistor before relay and capacitor in 12V rail. If this relay is not cast, it is possible to open and clean contacts to physically see it functioning and measure input voltage when pressing the button
Don't blow up, don't blow up........ Did you change the contactor? That's his fix for mystery issues!! And who would down-vote a failed repair? There is still something to learn from everything and we all can't fix everything. That Harmon Cardon I mention didn't have the 5V reference, as you did there. It was some lower voltage and after removing everything from the circuit and expecting something to be pulling it down the only thing left was the MCU itself. And yes, I did check the pull-up, it was a resistor network and was expecting that to be the issue and wasn't. Somehow the input pin next to it for the headphone sense was weird as well. Did that half ass repair with a resistor on that input pin to get the voltage right on the button sense pin. Anyway.... nice try on this one here. Guess you got tired of rabbit holes, I don't blame you.
Failure is part of life. It is what it is. Thanks for your content. 🙌
Some things are Done and just lasted as long as they did. You did more then any manufacture would. As they just would scrap it as a loss. You're a great teck!
Regardless of the repair outcome I always learn something from your efforts.
A friend of mine says that when you throw away "Black face" receivers, you should place them vertically so that you can fit more of them into the barrel.
I absolutely liked it. Amazing the amount of diagnostic you did on this. It was bugging you. I have one of these units in great condition appearance wise, but it will not output speaker level sound. Renders it useless other than maybe some kind of pass through unit that also isn't worth it because of its size.
Did you try the initialization process? PG 13 of service manual. Turn off, remove AC, hold A and B, plug in, entire display flashes at 1hz, release buttons. Just in case something in the code has got mixed up. Stranger things have happened :)
in part 1 yes I did
@norcal715 You can be considering the reprogram action of the processor. In this case you can procure the new PROM the software and the device to reprogram it. For this specific model I've investigate with a people that fix it. The problem is to procure the code for coping into the PROM
i love the way you think and make diagnostic
When you said you get different results each time you click that button makes me think of a TV I once had that didn't have a remote and sometimes when I would turn up the sound the channel would change and when I would change the channel the menu would pop up, or the TV would shut off. The replacement of the tact switches solved the problem. Maybe the tact switches on this unit are bad.
Maybe try replacing relay A+B and check transistor before relay and capacitor in 12V rail. If this relay is not cast, it is possible to open and clean contacts to physically see it functioning and measure input voltage when pressing the button
Ridiculous they don't have a removable bottom plate on various models.
Good troubleshooting skills. Maybe someone will leave a helpful comment and you will complete the repair.
nice to see failures, that's life.
Yup. What I say is "with every success comes a failure or two" it's a fact of life.
i enjoyed t he video....i learned some things from it :)
$58 incl shipping parts only on e by, same model.
What if it has the same issue though (like the famous Yamaha DSP IC failures)
Don't blow up, don't blow up........ Did you change the contactor? That's his fix for mystery issues!! And who would down-vote a failed repair? There is still something to learn from everything and we all can't fix everything.
That Harmon Cardon I mention didn't have the 5V reference, as you did there. It was some lower voltage and after removing everything from the circuit and expecting something to be pulling it down the only thing left was the MCU itself. And yes, I did check the pull-up, it was a resistor network and was expecting that to be the issue and wasn't. Somehow the input pin next to it for the headphone sense was weird as well. Did that half ass repair with a resistor on that input pin to get the voltage right on the button sense pin. Anyway.... nice try on this one here. Guess you got tired of rabbit holes, I don't blame you.
Do you watch Chris Stephens (HVACR Videos) That's where that came from.
@@norcal715 Yes, that's where the contactor reference came from. He loves changing contactors! lol
@@norcal715Is he the guy that had that little dog named Molly.
how do you use the dmm prob with the scope
Just with a clip lead attached to the probe and the test lead. I'm not worried about extra capacitance, just a result