Maker Pro
Maker Pro

Technics SA-GX710 receiver shuts on and off

musiclover777

Jul 7, 2012
2
Joined
Jul 7, 2012
Messages
2
Hey everybody,

My receiver shuts off after a few minutes of working fine, then turns itself on after like 10 minutes and keeps doing that. Turning itself on and off.

What could it be, can it be fixed and is it worth it? It is a great receiver with lots of features.

Thanks!

Dee
 

UnionTech

Mar 5, 2012
17
Joined
Mar 5, 2012
Messages
17
I would suspect heat and/or power supply. If your receiver is in an enclosure / entertainment center I would take it out and see if symptoms are the same or if it runs longer. If it persists open receiver and try again. I'm not sure about that model receiver but some have over current protection circuits and will shut off when over current condition is sensed (shorted speaker wires). Heat is the enemy of electronics, it could be a transistor getting hot and acting up causing over current circuit to kick on. If so you could try to isolate the output boards one at a time if possible till the bad channel is found then replace or just leave it out.

If you have a multimeter and are comfortable working around mains voltage you can just follow the voltage and see where it stops once it shuts off.
 

musiclover777

Jul 7, 2012
2
Joined
Jul 7, 2012
Messages
2
Amp shut-off problem

The receiver sits in a rack that is open on all sides. The cooling vents are on top and there
is a 2" space between the receiver and the next component on top. A couple of years ago
I forgot to turn the receiver off for a few days and it got pretty hot. It also gets hot after a few hours of operationg.
Receiver has a built-in fan that used to kick in at high volumes but it seemed to have stopped.
The fan does not come on at low and medium volumes.
Is there a fuse that controls the fan/overheat protection circuit? If so, I could replace that. If it's a transistor I probably could not.
I am not that comfortable with a multi-meter in a amp as complex as this.
Any more pointers are appreciated.
 

CocaCola

Apr 7, 2012
3,635
Joined
Apr 7, 2012
Messages
3,635
Receiver has a built-in fan that used to kick in at high volumes but it seemed to have stopped.
The fan does not come on at low and medium volumes

I believe you just answered your own initial question, the cooling fan has failed thus the receiver is overheating and shutting down...

Fix the fan and get it spinning again, my guess is that it's full of dust bunnies and/or the bushings/bearing have worn either way the fan is likely long expired...

As for a fuse or what not, I would suspect not, I would honestly not be surprised if it lacked thermostat control either... It's likely just 'on' when the receiver is on, and 'off' when the receiver is off...

Identify the size of the fan, and identify the supply voltage... Also identify if you are getting a supply voltage to the fan, initially or at a 'hot' running temp... With those two things identified you will know how to proceed, be it replacing the fan with a new one, of comparable size and voltage requirements or tracking down why it's not getting power, and still likely replacing the fan...
 

Solidus

Jun 19, 2011
349
Joined
Jun 19, 2011
Messages
349
The receiver sits in a rack that is open on all sides. The cooling vents are on top and there
is a 2" space between the receiver and the next component on top. A couple of years ago
I forgot to turn the receiver off for a few days and it got pretty hot. It also gets hot after a few hours of operationg.
Receiver has a built-in fan that used to kick in at high volumes but it seemed to have stopped.
The fan does not come on at low and medium volumes.
Is there a fuse that controls the fan/overheat protection circuit? If so, I could replace that. If it's a transistor I probably could not.
I am not that comfortable with a multi-meter in a amp as complex as this.
Any more pointers are appreciated.

Well, running it hot for extended periods would eventually work bad wonders on processors in the unit, so it may be that finally one hot period may have finally "killed" a circuit in it.

Are you sure there is an "overheat protection" circuit? A lot of overheating protections shut features down per a thermostat or some function. If you were just relying on one fan, one fan typically helps but it can't do all the work of getting all heat out.

Playing off what CocaCola said, if the fan is faulty then it could be throwing off the system. Maybe the device has a feedback loop to determine if the fan is working, if not, go to plan B, the shut down as I detailed above.
 

docb

Feb 11, 2010
131
Joined
Feb 11, 2010
Messages
131
I'd look at solder connections on the voltage regulators.
 

mechtronics

Aug 7, 2011
153
Joined
Aug 7, 2011
Messages
153
ya i would do some continuity testing on it, but it sounds like heat and current overload to me, some components might be damaged if this is the case.
and ya as docb said id look at the voltage regulators too.
 

docb

Feb 11, 2010
131
Joined
Feb 11, 2010
Messages
131
When you say it shuts off, is it power off, or the speaker protection relay clicking off?
 
Top