Hello i`have a nakamichi 420 power amplifier, which doesn`t want work. When i'm switching on, protection circuit is switching off. I haven't found anything, what makes this to do. Someone has an idea ? Thanks for all Joachim
Nakamichi 420 Poweramplifier repair idea ?
Apr 01, 2005
2 Replies
Output stage transistor/s have failed short circuit....???
Don't know about Nakamichi but 2 previous false activations of protection circuit faults I've come across concerned falsely recognised imbalance of main + & - rails. Fool the monitor of these rails into thinking they are balanced and 'fault' disappears. Then a matter of balancing up zeners / diff gain or whatever in the mionitor circuit to bring back into line.
Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on
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