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NAD 317 Amplifier not working - clicking noise

This is a NAD 317 which I purchased new almost fifteen years ago. A couple of weeks ago it failed to turn on and instead I heard a relay clicking noise at about 2Hz

I Opened it up and I concluded the relay clicking is the power relay.
According to the schematics that is relay RL501 right on the main power line. Looks like this relay is controlled by IC801 - port 18.
IC809 is labeled R264 and looks like it might be some sort of controller with several in/out ports and an oscillator.

Can someone help me figure out what the problem might be? My hope is that this controller is not faulty but some other signal is actually telling this controller to kill the power.

Any help would be really appreciated.

Thanks!



NAD 317 Amplifier not working - clicking noise

C502 (1000uf, 16 volt) and C505 (10uf, 50 volt) should be replaced. This is standby power filtering. Check for poor solder connections in this circuit.
It should be noted that the schematic listed here in the library is wrong as far as the wiring of the standby transformer. Also, C505 does not need to be 50 volts; 16 will do.
You may have a bad regulator for standby power; unlikely though.

NAD 317 Amplifier not working - clicking noise

Johnnysan,
I am stunned! I replaced the two capacitors you indicated and now it works!
How did you know?
And how can these two capacitors stop working? After all this is a very simple power filtering! And usually capacitors either work or they blow up... No half-way.

Anyway, I thank you infinitely for your suggestion and I hope I'll be able to help someone else like you did.

thanks

NAD 317 Amplifier not working - clicking noise

I'm a tech.
Capacitors, especially electrolytics, fail in many ways. The 1000uf cap probably just opened up or lost much of its ESR (effective series resistance). Heat and AC across a cap make them fail also; power supply filtering is a tough job. Using too small a value for filtering will cause problems because that little bit of AC will make a cap fail eventually. If you see a cap near a heat source like a power resistor or large transistor it is sometimes advisable to move it slightly like bending it over on its side, if possible.
Of course, the new cap will probably last as long as the old one.

NAD 317 Amplifier not working - clicking noise

Johnnysan,
What you are basically saying is that the problem I have with this unit is with the standby power.
I didn't notice any bulged capacitors or anything that looked fried but I will now look closer at that section of the circuit and see if I get 5V out of the standby power.
Thank you and I will let you know what I discover.

NAD 317 Amplifier not working - clicking noise

Hi,
You are lucky. From the people I see responding to questions/issues on this site, Johnnysan is one of the "Higher Quality Component level Techs" I have seen.
Tom