Need Help regarding Yamaha RXV371. No Sound Output

[Hemant Choudhary]

Hello Everyone,

Please assist me in getting help on the below.

I have a Yamaha RVX371/3064 that has stopped working all of a sudden, while every thing was good.

Now the status is, it does power up but there is no Speaker symbol that i used to get after the relay clicks.
The relays do click now but the speaker symbol does not appear.

i intend to repair it myself, as it is out of warranty. i do have basic troubleshooting experience but not much to repair it all by my self.

Please assist.

Thanks,

 

[davenn]

hi
welcome

first thing to do is find a service manual
then you and those here have something to go on

 

[73's de Edd]

Sir . . . . .Hemant Choudhary . . . . . . .

Dust covers off ?
And are you to pages 81-82-83 of the schematics and have you located the:
STK433-130
STK433-330
Pair . . . . both on the schematic and physically on the chassis ?

73's de Edd

 

[Hemant Choudhary]

i was able to get the service manual. Now will start with the troubleshooting..will keep you all posted.

 

[davenn]

i was able to get the service manual. Now will start with the troubleshooting..will keep you all posted.

got a link so I can get it too ?

 

[Hemant Choudhary]

http://elektrotanya.com/yamaha_rx-v371_htr-3064_av_receiver.pdf/download.html

Here is the link.

 

[Hemant Choudhary]

hi,

the big porblem starts now, i tried getting the stk's both of them but here in mumbai, i am not getting them.

tried hard. people only have one.

now i have a feeling that its going to take more than i thought.

 

[Hemant Choudhary]

Hey,

without doing any thing, now the unit does not power up at all..no relay clicks..no display. Does that mean i will have to start looking for trouble in the power supply section.

also, how to be sure that the out put STKs ( both of them) are to be replaced..
there must be a way to be sure.

Please guide me further.

regards

 

[davenn]

Does that mean i will have to start looking for trouble in the power supply section.

the best place to start

but isolate the PSU stage as much as possible from the rest of the system
Because if the PSU has failed, it may have been caused by a fault somewhere else in the system

 

[Hemant Choudhary]

when we reset the receiver with tone control and power button..the receiver clicks twice..once to turn on then to turn off.

also, by this way i was able to measure the voltages at the output resistor but all were 0 volts.

now no ideas where to go ahead.

please advice

 

[kellys_eye]

Did you isolate the PSU outputs? i.e. disconnect the power supply section from the rest of the electronics?

 

[Hemant Choudhary]

Yes, the standby psu was isolated and checked for voltages.

i,ll post the reading from the pins that goes to the amplifier..along with conector numbers.

Regards,

 

[Hemant Choudhary]

Also, one more question

Why isn't the display coming up and showing the error codes, is it that it only displays minor faults and when there is a serious fault, the display also does not work.

 

[Hemant Choudhary]

MG= 0v
ACDET = 9.8v
PRY = 0v
S9 = 14.6v

 

[kellys_eye]

Those are the voltages on the 'standby' power supply.

You need to check the supplies (+/-12V) on CB134 (MAIN 1) and on the 'digital' connector CB131. Test and report.

 

[Hemant Choudhary]

CB134

NC...0V
+12 V...9.8V
AGND..0V
-12V...-10.2V
PRV...0V
VP...-29.3

 

[Hemant Choudhary]

these are the details when the receiver is turned on for the short time before shutting down..

 

[Hemant Choudhary]

here are the details of CB131

N-PDET....3.3*
PWR_RY..2.5
N-CPU-RST..3.3*
+3.3M...3.3
MG...0
9T...7.2
AG...0
+5A...3.8
+5I...-1.22
IGND...-1.25
+7D...0.47
DGND...-0.11
TMH1..2.9*
TMH2...3.3*

* marked are the readings that changes by 0.05 to 0.07 volsts, when the receiver is "ON" for the brief moment.

Please assist

 

[kellys_eye]

What are you using to measure those voltages? What range are you switched to? Where are you taking your 0V reference from?

 

[Hemant Choudhary]

i am using digital multimeter..measures on the range of 20 and 200 volts..and using chasis ground as referance..