I have the original 3020 amp and the symptoms indicate carbon buildup in the power switch that needs cleaning according to what I read in the internet.
has anyone here taken apart this switch and can give me some hints as to doing it as it doesn't look like any switch I have worked with before and don't want to take apart the wrong way.
thank you.
has anyone here taken apart this switch and can give me some hints as to doing it as it doesn't look like any switch I have worked with before and don't want to take apart the wrong way.
thank you.
The original model had a standard TV etc. pushbutton power switch dating from the 1970s and it didn't need to fit to the PCB. I have replaced them with similar from old, scrapped TVs obtained from recyclers but I still see them around as new parts in catalogues, on the internet, Amazon even. They are certainly still available in various DPST types that are suitable for this model, at least.
Most were assembled with rivets to prevent tampering, since they are connected to mains voltage and should be maintained sealed as is or replaced. Don't tinker with mains switches for safety's sake. Be sure to insulate the wire connections and leads with sleeving for safety.
Often, a noise problem develops with ageing of the safety capacitors mounted across the switch contacts too. They should be replaced with similar (4.7nF) X2 rated caps.
Most were assembled with rivets to prevent tampering, since they are connected to mains voltage and should be maintained sealed as is or replaced. Don't tinker with mains switches for safety's sake. Be sure to insulate the wire connections and leads with sleeving for safety.
Often, a noise problem develops with ageing of the safety capacitors mounted across the switch contacts too. They should be replaced with similar (4.7nF) X2 rated caps.
thanks for the advice
I went to a broken tape deck about 20 years old and took the power switch and associated cap and moved them over to the NAD and all is good !!!!!!
I went to a broken tape deck about 20 years old and took the power switch and associated cap and moved them over to the NAD and all is good !!!!!!
Good to hear 🙂 Generally with these push on - push off power switches, the problem is mechanical wear and arcing at the sliding contacts. You can't see this but the contact metal is thin and erodes away, leaving low contact pressure with ever decreasing current capability. The only sensible solution is replacement, noting the current rating is sufficient and then some, to withstand the damage due to inevitable arcing since the action is slow. A swift push rather than a slow a slow or gentle one at power up or down, can only help.
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