Marantz SR5300 Receiver Problems

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I have a Marantz SR5300 Home Cinema amp which has a problem. When I switch on, the power led lights up, but that is it. No relay click, no display, nothing.

I am just wondering if anyone has any knowledge of common faults with these units, or has any ideas of how to find the fault.

I have removed all of the boards at the rear of the unit from the "motherboard" one at a time and still nothing happened so I don't think the fault is with any of those.

I am quite stuck as to where to start looking.

Regards, Lee.
 
Are you hearing the speaker relay click in? If your not there could be a malfunction that will probably end up being excessive DC on the output of the amplifiers. The protection circuit monitors the amplifier output and latches up the speaker relay when everything is ok. There could also be a problem with the preamp section of the unit. I have seen this result in a no display condition.

The company I work for sells Marantz as a product and they haven't had a real good track record. If you aren't skilled in the field I would send it to a Marantz repair station. If it has taken a hit as a result of a storm I would head to the nearest dumpster and deposit it.
 
Hi again. I think I have narrowed it down a little.

I have removed all of the plug-in boards from the mainboard. I have disconnected the board with the output transistors.

If I disconnect the main power feed from the mainboard and power on, the display works, registers volume and selects sources so I don't think the preamp / control section is faulty.

With the main supply reconnected I read -50v across one res. cap but 0v across the other. If I then press a source select button the display flickers and relays click and the non-charged cap charges to +50v. That cap then discharges very, very quickly making it impossible to check voltages in the circuit. The other cap, negative supply stays charged for ages.

Any ideas anyone?

Regards, Lee.
 
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