I just purchased a Teac A-4010s that was made in 1970. I am in the prosses of going through it and doing what I can to fix some of the issues it has. I am not an experienced tech but I can do simple work. It seems that the two solenoids are running hot. I don't know what too hot is for these units but the front panel get hot to the touch. I can get to the leads on the one and measured 83 vdc across it. I can't find anywhere that list what that voltage should be. I appreciate any help I can get.
You would need to look at the circuit diagrams, locate the coils and see how the coils are driven and by what voltage.
I've found what looks like the appropriate section and it looks to be an 85 volt AC feed feeding a half wave rectifier. I can't find any reference to the cap but it might be worth checking it OK if it is an electrolytic.
I suspect the heat will be normal judging by the general design.
I suspect the heat will be normal judging by the general design.
There is a capacitor across the leads of both solenoids, the brake and the capstan. My diagram shows a capacitor at each solenoid. Some solenoids work with two voltages, one to kick it in and the other lower voltage to maintain it in. That is supposed to keep the heat down. Do you think that is what those capacitors is supposed to do?
I worked those a long time ago. Front panels did get warm after running for a while. Do the coils have a burnt smell to them? A slight sweet-burnt smell is probably normal by this time.
Solenoids got warm. Many had a pull-in voltage, then they dropped the voltage down to a holding voltage. This is an earlier machine, so maybe if the voltage is correct you can make a resistor shorted by a relay that drops out after 1/2 sec or more. You don't need the full pull-in voltage to maintain the solenoid pull.
Look at newer ones like an A3440, I know an 80-8 dropped coil voltage for sure.
Solenoids got warm. Many had a pull-in voltage, then they dropped the voltage down to a holding voltage. This is an earlier machine, so maybe if the voltage is correct you can make a resistor shorted by a relay that drops out after 1/2 sec or more. You don't need the full pull-in voltage to maintain the solenoid pull.
Look at newer ones like an A3440, I know an 80-8 dropped coil voltage for sure.
It does smell like cheap perfume after it runs for awhile. I will let it go and see how if runs and if it gets too hot maybe I will to the resistor Idea.