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Yamaha R-N602 Switches itself off

I'm guessing it's that IC267, should look like a small black transistor (TO-92 shape). Pieter, please post a pic of the other side of the board.

Also, please measure the voltage on it, Ticla mentions 3.3v.


-F_D
 
As per the manual page 70

ic short out.png

The IC is a LM19CIZ/LFT4 with details as here

EDIT: Using the pin designation as per the specification sheet, then the bridge should be as shown in the red jumper line. Refer to the post below.
 
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Thank you mygoggie , will bridge it out tomorrow evening.
If one wants to do it the right way, must I bridge it out or replace the IC?
 
If I look at the sketch on P70 I then presume the text on the pc board points to these connectors.
 

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pietpetoors said:
If I look at the sketch on P70 I then presume the text on the pc board points to these connectors.
Click to expand...
It is a bit confusing as the manual and the IC's specification sheet differ as to which pin is which. Look on the IC exactly which model you have. The LM19CIZ/LFT4 specification sheet shows it to be as follows looking from the bottom of the IC.

1714330557369.png
 
Between 3.3S and DGNG connectors it measures 3.306 volt.
I decided to test it and sommer short the 2 connectors out with the multi-meter probe. The moment I connected 3.3S and DGNG the amp switched off in exactly the same way it does when it switch off by itself.
 
I bridged those connectors and it switched the amp off.
I now pulled the plug out of that small pc board and the amp is still working.
 
I bridged the other 2 pins now and it did not switch off the system.
But if I pulled the plug and the amp is still working, won't it solve the problem? My electronic knowledge is limited but; There is heat transfer gel between the IC and heat sink. It seems to me this IC must send a signal to the main board if it overheats. So if I unplug this whole circuit and the amp is still working, it means that this board can no longer send a false signal to the main board. Bridging it out will disable this circuit, unplugging it also disables this circuit?
 
pietpetoors said:
I bridged the other 2 pins now and it did not switch off the system.
But if I pulled the plug and the amp is still working, won't it solve the problem? My electronic knowledge is limited but; There is heat transfer gel between the IC and heat sink. It seems to me this IC must send a signal to the main board if it overheats. So if I unplug this whole circuit and the amp is still working, it means that this board can no longer send a false signal to the main board. Bridging it out will disable this circuit, unplugging it also disables this circuit?
Click to expand...
If you unplug the sensor and the amp is still working, then there is something else wrong. The IC gives out a specific voltage depending on the temperature of the environment is in. See the table below. If it gives 0 V (unplugged) then the monitoring circuit will be "reading" the temperature circuit as 0V. This voltage will mean that the temp is way more than +130°C.

If you bridge the Vin and Vo then the monitoring circuit will read that the temperature is below −55°C and it should still be working.

So, I do not think it is this circuit that is the problem. The temperature monitoring circuit should switch the amp off immediately when you unplug the wiring ribbon. It does not, so there is something wrong with the monitoring circuit.

1714334442893.png
 
I used it the rest of last night with the small circuit unplugged. I switched it on this morning and used it for about an hour before I went to work, with the small circuit unplugged. Got home this afternoon, switched it on. It just showed "Mains On" and then switched itself off. Opened it, plugged in the small circuit, switched it on and then it is working again. Something else I noticed while working on it. I've put cover back on. When I lean the soft part of my forearm on the cover I can feel a slight tinkle from electricity. When I touch the cover with my hand I feel nothing. I unplugged the main power to make sure it is not my imagination and definitely when power is on I feel feedback through the metal casing. I had a surge protector plug on it, changed it to a normal plug and the feedback is still there.
 
I have not checked the schematic but sometimes a cap is placed between the AC Mains input and chassis ground. This is typically a low-value cap but there is quite possibly a teensy leakage through it, not enough to really cause any trouble.

-F_D
 
Hold thumbs I might have found a way around the problem.
Short story: I disabled it's ability to switch to sleep mode.
Test: Put it on USB, repeat, has been running 28 hours non stop now.

Long Story:
Since the Yamaha switch off continuously I stopped using it. Used my Klipsch speaker via BT instead.
Bought a used CD and wanted to test it to see if it is fine. Listened the whole CD on Yamaha without problem. After CD finished, was busy working, did not want to get up, so just resumed playing BT on the Klipsch. After a long while I realized the Yammie did not switch to sleep mode as it usually would on USB or Net Radio. Went into the MusicCast app and disabled sleep mode. Started playing USB on repeat, has not switched off again yet, 28 hours later.
If this was the problem then my theory would be that whatever circuit tells the sleep mode circuit that the unit is still active, does not communicate properly with the sleep mode circuit. Still bit early to tell because it happened twice now that I opened it, check all plugs, soldered some points and then it was working fine for 3 weeks and then started again. So far for now it looks good, but I will have to use it for longer to say for sure.
 
:( Sleep Mode was false hope.
I left home for the evening after Amp was working for 36 hours. When I came back home this morning i was dead again. Switched it on, decided to play CD and see what happens, played 2.5 tracks and then switched off again. The problem is not constant at all. Back where I was.
 
Well ventilated and I did run it with top cover removed. Heat sink remains cold. Heat sink I can hardly feel more heat than the casing. Power supply about 35 degrees Celsius while room is 22. . With all these tests the volume is low, background music style.
 
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