31-12-2022, 02:47 PM
I agree with Trevor. Make zero assumptions. Approx order to check. 5 & 6 could be swapped.
1) Check speaker continuity as the connection to voice coil can corrode (more likely than overload).
2) Check speakers actually connected (any switch on external speaker sockets or mute or whatever)
3) Check PSU quickly.
1, 2 or 3 is the most likely.
4) Quickly check the output voltage at amps.
5) See does record-player or radio feed tape socket. Record player cartridges fail.
6) Add input signal to tape socket and thus verify if main amp is working, if not, then see where signal fails. Did 1 to 4 really pass?
Can be a dried out electrolytic or a locfit type transistor if used (replace with similar TO92, they all have TO92 versions) rather than output transistors. Or the bias can be faulty if there is a pot.
1) Check speaker continuity as the connection to voice coil can corrode (more likely than overload).
2) Check speakers actually connected (any switch on external speaker sockets or mute or whatever)
3) Check PSU quickly.
1, 2 or 3 is the most likely.
4) Quickly check the output voltage at amps.
5) See does record-player or radio feed tape socket. Record player cartridges fail.
6) Add input signal to tape socket and thus verify if main amp is working, if not, then see where signal fails. Did 1 to 4 really pass?
Can be a dried out electrolytic or a locfit type transistor if used (replace with similar TO92, they all have TO92 versions) rather than output transistors. Or the bias can be faulty if there is a pot.
