Harman Kardon AVR 370

[Technik92]

Hello, I have a problem with the harman kardon AVR 370 does not start after turning on, it immediately turns off, I borrowed the power supply from a colleague and its power supply works, so the reason will be in my power supply.
Has anyone had a problem with this power supply or has it repaired and knows which part could get stuck in it?

[budm]

Re: Harman Kardon AVR 370

Did you look for service manual?
https://elektrotanya.com/showresult?...oria=&kat2=all

[budm]

Re: Harman Kardon AVR 370

BTW, you also need to attach some pictures for us to look at so we can see what we are dealing with.

[bluebear]

Re: Harman Kardon AVR 370

Depends what you mean by "immediately turns off".

Check capacitor C983 and C939, they seem to fail fairly regular. Without any more specific details its hard to say.

[Technik92]

Re: Harman Kardon AVR 370

after disconnecting the -50 V and + 50 V bus connector, the receiver starts without problems. Below are links to movies where I show the problem and 2 movie on which the receiver works after disconnecting the 50v plug.


https://www.youtube.com/watch?v=KyDg...ature=youtu.be



https://youtu.be/6l0qi-I6M2k

[R_J]

Re: Harman Kardon AVR 370

With CN20 disconnected from the amp board, what voltage do you measure on CN20 on the power supply? There are two seperate smps's for the +/- 50v, they are basically identical except for where the -50 takes its output. so it should be easy to check components between them.

[Technik92]

Re: Harman Kardon AVR 370

Black and red = 54V
Black and white = 54V
White red = 107V



The power supply is functional because I have a spare one.

When I pull this tape, it runs without promblem

[R_J]

Re: Harman Kardon AVR 370

Black and red = 54V
Black and white = 54V
White red = 107V



The power supply is functional because I have a spare one.

When I pull this tape, it runs without promblem

You said the problem is in your power supply and NOW you say it is Functional? which is it?

I borrowed the power supply from a colleague and its power supply works, so the reason will be in my power supply.

When you tried your friends power supply in YOUR amp, did you have audio from ALL speaker outputs?

[Technik92]

Re: Harman Kardon AVR 370

Sorry, I checked the power supply recently because I forgot to connect 50v.

Tomorrow I will check if the sound is.

I will look for the problem of this short circuit because when I connect the tape, it is short circuit immediately

[Technik92]

Re: Harman Kardon AVR 370

I checked and no sound.

I think I have already found the reason for the short circuit at the SURR LEFT speaker output after turning on the power was 54v and dropped to 27v as in the photo after desoldering 2 ends B1647 and D2560 the amplifier works and I think I will order these 2 parts burned tomorrow

[R_J]

Re: Harman Kardon AVR 370

Make sure to check the dual emitter resistors and also the 3.3Ω base resistors. If the base resistors are open, you would need to check the driver transistors also. You should also check R821 & R822 (18Ω) If you are lucky only the outputs are bad

[budm]

Re: Harman Kardon AVR 370

make sure to check the dual emitter resistors and also the 3.3Ω base resistors. If the base resistors are open, you would need to check the driver transistors also. You should also check r821 & r822 (18Ω) if you are lucky only the outputs are bad

+1

[Technik92]

Re: Harman Kardon AVR 370

Ok, I'll check it tomorrow

Through these 54v I have damaged the central speaker CEN-TS60 and the loudspeaker already has someone else suggest what could have fallen in the inverter?


Such parts are there:
3.6uf 100v
2x 4.7uf 100v
26uf 100v
200uf 100v

10w40ohm
10w2ohm

[Technik92]

Re: Harman Kardon AVR 370

Make sure to check the dual emitter resistors and also the 3.3Ω base resistors. If the base resistors are open, you would need to check the driver transistors also. You should also check R821 & R822 (18Ω) If you are lucky only the outputs are bad

Hello, I replaced these damaged parts now starts and after 10s turns off by itself

[R_J]

Re: Harman Kardon AVR 370

What damaged parts did you replace? Did you just replace the 2 transistors?
Check the voltage on pin 1 &2 of CN66? This is connected to the emittter resistors, check this voltage before the amp shuts down.

[Technik92]

Re: Harman Kardon AVR 370

So I replaced 2 transistors B1647 and D2560 + R817 3.3Ω.
Voltage on pin 1 & 2 CN66 = 17,2V

[R_J]

Re: Harman Kardon AVR 370

That voltage on CN66 should be close to 0 volts.
If R817 was damaged (open) then you need to check all the driver transistors and resistors. Check Q856,Q876,Q886,R786,R776 and all the the other transistors and resistors in that part of the circuit. You can compare values with a working channel.

[Technik92]

Re: Harman Kardon AVR 370

ok Q856 is broken tomorrow I will buy these hi the rest seem ok

[Technik92]

Re: Harman Kardon AVR 370

You can recommend a replacement because I can't buy the same model anywhere HVTKTD600KGR

[Technik92]

Re: Harman Kardon AVR 370

ok i found and ordered 2SD600K Y TO126 NPN 100V 1A 130MHz