Marantz SR5009 turns off and on

Paal1

Novice Member
Hi all,

Lately my Marantz SR5009 has started to turn itself off after around 20 min playing at low volume.
After turning off, it immediately turns back on, and then off again after some seconds and so on until it is turned off manually (the display shows "initializing" or something similar until it turns back off).

In protection history mode the display says «Protect history: NO». Indicating no thermal protection or similar.
No speaker wires are shorting. It is placed in a well-ventilated place (I also tried having it at the middle of a wooden floor, but it made no difference).

After removing the cover, it played for hours without any complaints. I then put the cover loosely on top, with no screws. After approximately 20 minutes it turned itself off again.
A weak «buzz» (similar to frying an egg, just a lot lower volume) could be heard from the SMPS area (where the power cable is connected) when putting my ear close to the top of the receiver.

The "buzz" gradually went away in the course of 5-10 seconds, after lifting the cover off. Then the receiver was ready for playing music again.

Although I could not see any dust from above, I blew where I could, without removing any circuit boards. There was almost no dust to see inside, but I must admit I don’t know how it looks where I cannot see without removing any parts.

After blowing, the receiver played music for around 2 hours WITH the cover loosely on top, before turning off.

If anyone has any advice regarding the cause and/or where to start the troubleshooting, I would really appreciate it.

Thanx
 

dobrykamil

Well-known Member
I believe you might have issue with power supply. I've seen this kind of problem with Denon avr-x2300 which use very similar or perhaps even identical psu. Remove top cover, switch it on, get a hair dryer and blow some hot air around psu board for 2-3 minutes.
 
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Paal1

Novice Member
I believe you might have issue with power supply. I've seen this kind of problem with Denon avr-x2300 which use very similar or perhaps even identical psu. Remove top cover, switch it on, get a hair dryer and blow some hot air around psu board for 2-3 minutes.
Thank you very much, dobrykamil!

I think you are right. Using a hot air gun set to 80 deg C, it took around 10 seconds for the receiver to shut down.

Any suggestion how to proceed in order to localize the faulty component?

I will of course take full responsibility, should I fail to repair it myself.

Thanks once again!
 
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dobrykamil

Well-known Member
Hi.
I really wish I had an easy answer for you. Obviously there is a faulty component like capacitor, diode, smps pwm controller etc. It could be in the high or low voltage side of the power supply.
In this case I would remove psu, put 3 or 4mm nozzle on my heat gun and start heating each component one by one until amp switch itself off.
 
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