This was very helpful. 😁I have a Sony mini system that suffers from microswitches that do random weird things. Now I know how to repair it thanks to you.
I learned about this when I was trying to fix a Pioneer CD player with some buttons that didn't work at all. The switches seemed fine, so I looked into the service manual and sussed out the whole resistance thing. It's a good public service to get this info out. In my case though, some numpty had done something with the control board, and there was a solder blob causing a short between a couple of lines on the control IC - got rid of that and all the buttons started working, although as I had bought replacements (which were not cheap, as Pioneer in their infinite wisdom used 2-pin tact switches which are much rarer) I replaced them anyway as a few were "soft" and/or required a harder push to get them to work.
It kind of blew my mind a little bit to be honest as I didn't know myself until recently. I guess it's a great way to pack in all those buttons without much space taken up by tracks? But then more components and resistors!
@@pwrestoration I guess it's also so you can have a control IC with a single analogue input rather than a dozen binary ones. Although I have to say I was kind of expecting either a matrix (like a computer keyboard) or a multiplex (like an LED display).
Tactile switches tarnish over time so the resistance when pressed is higher than zero. I've had great success removing them and soaking them in alcohol in a zip lock bag and ultrasonic cleaner. The alcohol evaporates pretty quickly. I'm experimenting with another liquid cleaner specifically for removing tarnishing and oxidisation. Some decks use tactiles that are difficult to get hold of so cleaning them this way is a good option. I've not had any returns yet. Hahaha, I just heard the comment about tapeheads forum. Totally get where you are coming from, but there are reasonable folk on there that do take their medication 😅
THanks for this video! It's rally needed as it's not intuitive. I've figured out the same when a second-hand JVC AVR was showing the same issues.The IC measures the resultng voltage from the resistance in the circuit and figures out what it was commanded to do. It's interesting the values are chosen with such odd values: 2, 2.7, 5.6, 10, 30. Pressing any combination of two buttons will not result in a duplicated resistance value, since functions like next song require pressing play+rewind. I tried the 12Voltvids solution of cutting tem open and cleaning the little metal dome and contacts for oxidation, but it's just so much easier to order replacement tactile buttons.
I considered it too, but when I realised they were £3 delivered for a bag, It just wasn't time / cost effective. Plus with new switches it feels reeeealy nice now
Great video as always. Quick question - do you know of any available replacements for the mode select motor? This seems to be the same in most Sony decks, I have a TC-K 620 which seemed to have been incorrectly reassembled during a belt change and it seems the mode selection motor is dead. Would be keen to try and swap it for a new replacement one if such are available.
Hey, thanks! That's a difficult one. I've always ended up replacing from donor decks but that motor hardly ever dies. Does it spin when powered directly from a power supply? I think it's 6v but it's an odd size, and a long shaft too. I would say definitely have a good test of it and a hunt round for something else causing a problem. If it does spin when powered directly with 6v it could be a cap / resistor in the transport that's failed. If not, and you get mega stuck, email me. I might have one lying about you can have 👍
I just have to add here, I'm absolutely humbled by your donation / super thanks thing. Its the first time someone has done it in the entire history of me doing this channel. I had to Google what it was! Many, many thanks. It is hugely appreciated. Peace!
I think this is the problem on my tc-ke400s. None of the buttons do what they are supposed to do and even pressing play make the deck rewind but only the one real turns which chews the tape up!! I don’t suppose you know if all Sony decks have the same buttons so I can order some before taking the deck apart?
I wonder why they spend the effort with all these resistors, just to spare a few wires from the pcb to the microcontroller. It seems to me as if they ran out of digital I/O pins and had to do the resistor trick, where they only need a single analog input. Or maybe the flex cable and the connector become cheaper when they have a few less wires, and that overweighs the cost of the resistors.
It's bamboozling, it's not like they need to save track space. Maybe when they were first introduced they took up more room, and they just.. retained it?
Thanks for sharing this, Paul. I never knew this, quite ingenious design.
I was actually quite impressed someone not only came up with the idea but also it was retained and universally used!
Ah yes! The tactile switches replacement. My favourite part during a tapedeck servicing.
Hvala na objašnjenju ,imam upravo taj problem sa mojim pioneer dekom.
This was very helpful. 😁I have a Sony mini system that suffers from microswitches that do random weird things. Now I know how to repair it thanks to you.
I learned about this when I was trying to fix a Pioneer CD player with some buttons that didn't work at all. The switches seemed fine, so I looked into the service manual and sussed out the whole resistance thing. It's a good public service to get this info out.
In my case though, some numpty had done something with the control board, and there was a solder blob causing a short between a couple of lines on the control IC - got rid of that and all the buttons started working, although as I had bought replacements (which were not cheap, as Pioneer in their infinite wisdom used 2-pin tact switches which are much rarer) I replaced them anyway as a few were "soft" and/or required a harder push to get them to work.
It kind of blew my mind a little bit to be honest as I didn't know myself until recently. I guess it's a great way to pack in all those buttons without much space taken up by tracks?
But then more components and resistors!
@@pwrestoration I guess it's also so you can have a control IC with a single analogue input rather than a dozen binary ones.
Although I have to say I was kind of expecting either a matrix (like a computer keyboard) or a multiplex (like an LED display).
Tactile switches tarnish over time so the resistance when pressed is higher than zero. I've had great success removing them and soaking them in alcohol in a zip lock bag and ultrasonic cleaner. The alcohol evaporates pretty quickly. I'm experimenting with another liquid cleaner specifically for removing tarnishing and oxidisation.
Some decks use tactiles that are difficult to get hold of so cleaning them this way is a good option. I've not had any returns yet.
Hahaha, I just heard the comment about tapeheads forum. Totally get where you are coming from, but there are reasonable folk on there that do take their medication 😅
THanks for this video! It's rally needed as it's not intuitive. I've figured out the same when a second-hand JVC AVR was showing the same issues.The IC measures the resultng voltage from the resistance in the circuit and figures out what it was commanded to do. It's interesting the values are chosen with such odd values: 2, 2.7, 5.6, 10, 30. Pressing any combination of two buttons will not result in a duplicated resistance value, since functions like next song require pressing play+rewind.
I tried the 12Voltvids solution of cutting tem open and cleaning the little metal dome and contacts for oxidation, but it's just so much easier to order replacement tactile buttons.
I considered it too, but when I realised they were £3 delivered for a bag, It just wasn't time / cost effective. Plus with new switches it feels reeeealy nice now
@@pwrestoration I bet! nothing like good look and feel to make a machine act like new.
good explanation and good tips !
Great video as always. Quick question - do you know of any available replacements for the mode select motor? This seems to be the same in most Sony decks, I have a TC-K 620 which seemed to have been incorrectly reassembled during a belt change and it seems the mode selection motor is dead. Would be keen to try and swap it for a new replacement one if such are available.
Hey, thanks! That's a difficult one. I've always ended up replacing from donor decks but that motor hardly ever dies. Does it spin when powered directly from a power supply?
I think it's 6v but it's an odd size, and a long shaft too. I would say definitely have a good test of it and a hunt round for something else causing a problem. If it does spin when powered directly with 6v it could be a cap / resistor in the transport that's failed.
If not, and you get mega stuck, email me. I might have one lying about you can have 👍
I just have to add here, I'm absolutely humbled by your donation / super thanks thing. Its the first time someone has done it in the entire history of me doing this channel. I had to Google what it was!
Many, many thanks. It is hugely appreciated. Peace!
@@pwrestoration You are absolutely welcome. Keep those videos coming :)
I think this is the problem on my tc-ke400s. None of the buttons do what they are supposed to do and even pressing play make the deck rewind but only the one real turns which chews the tape up!!
I don’t suppose you know if all Sony decks have the same buttons so I can order some before taking the deck apart?
I'll be honest you really need to take it apart and measure your switches.. it could be your issue!
Thanks mate. That makes sense. I’m just worried I’ll forget how to put it back together if it’s apart for too long 🤣
I wonder why they spend the effort with all these resistors, just to spare a few wires from the pcb to the microcontroller. It seems to me as if they ran out of digital I/O pins and had to do the resistor trick, where they only need a single analog input. Or maybe the flex cable and the connector become cheaper when they have a few less wires, and that overweighs the cost of the resistors.
It's bamboozling, it's not like they need to save track space. Maybe when they were first introduced they took up more room, and they just.. retained it?