Well well, you were right, the R334 was broken even though it looked fine. But the relay doesnt kick in, sound are present in both channels when manually forcing the relay, so what can it be?
Also the balance switch does not work..?? Weird, full sound either way.
Also the balance switch does not work..?? Weird, full sound either way.
Had to use a 39Kohm resistor instead of the original 49, could this be it? Not that I need the balance function but would be nice to get the relay to function normal.
Have you checked the resistor in both channels? Have you measured DC offset on output? Alternatively, there could be something broken in the protection circuit itself. Balance not working seems pretty strange unless you are running the signal directly into the power amp. Could be the pot or possibly damage to tracks on the board.
I repaired one of those NAD 304:s earlier this year. Both channels had their 47k resistor bad. The relay wouldn't close as there was a small DC offset on the output.
I repaired one of those NAD 304:s earlier this year. Both channels had their 47k resistor bad. The relay wouldn't close as there was a small DC offset on the output.
Dc offset, do I just measure across the speaker terminal? I have a 218 with serious offset problems in another thread, if you care to make a coment.
Yep, short input, and measure DC on output... significant DC would prevent your relays from connecting a load.
Yes, and of course you'll have to measure before the relay unless you have bridged it. If the 47k resistor fails the symptoms might seem a bit strange - with no or low bias current through the input stage the output will not center correctly. There will be no bias current through the output stage either. But you say it amplifies music which might suggest the problem might lie elsewhere. If the resistor is totally open it will not work at all. If it just has gone high in value it might almost work though. Have you checked the output of the regulated supply? The input stage of the power amp looks like its powered from there.