Center channel delay

[Brian Allen]

Hi all. I have a Yamaha RX-V373 receiver. My center channel isn't coming on right away - it actually takes ~10 minutes to turn on. The receiver has always made an a 'click' noise when turning on, but now it makes a second 'click' noise when the center channel decides to come on. Any ideas?

 

[TLS Guy]

Hi all. I have a Yamaha RX-V373 receiver. My center channel isn't coming on right away - it actually takes ~10 minutes to turn on. The receiver has always made an a 'click' noise when turning on, but now it makes a second 'click' noise when the center channel decides to come on. Any ideas?

The click is the relays connecting the speaker. The delay is to stop the turn on thumps that many, especially cheaper power amps have when they turn on. The delay prevents speaker damage.

Now these delay circuits are almost always based in the ubiquitous LM 555 timer IC.

Now the way this works is this: - The output to the relay is from pin 3.

The delay is set by the time it takes to charge the 100 mf cap. So increasing the value of the 47 K ohm resistor or the 100 mf cap will increase the delay.

So I suspect the the timer components of the LM IC circuit have wandered out of spec. with it taking a long time to charge the cap, and trigger output at pin 3 to close the relay on that center channel.

So if I were to service it I would identify that timer circuit and check the value of the timer components, and replace as required. It might be the IC but much more likely a problem with the timer components.

The above circuit just shows a delay circuit for an LED turn on. For speaker delay the relay solenoid coil would replace the LED.

This is a problem that for once should be eminently serviceable.

 

[Brian Allen]

By eminently serviceable, do you mean by yours truly or taking it to somebody? If the latter, what would you estimate I should expect to pay for the repair?

I'm not exactly electronically inclined, but I did just get done wiring a bathroom haha (joke). Thank you, TLS Guy, for the thoughtful post and help!

 

[TLS Guy]

By eminently serviceable, do you mean by yours truly or taking it to somebody? If the latter, what would you estimate I should expect to pay for the repair?

I'm not exactly electronically inclined, but I did just get done wiring a bathroom haha (joke). Thank you, TLS Guy, for the thoughtful post and help!

If you have not done any service work or handled a soldering iron, then not you.

Service techs are hard to find, so you might have to send it to a service center.

I don't know how hard it is to get to these components as they never issue service manuals. I'm going to guess that assembly fixing the problem and reassembly will be 2 to 3 hours. Rates will be around $75 to $100 per hour I expect.

 

[Brian Allen]

That's what I needed to hear. Thank you again for the hasty replies and help!

 

[tyhjaarpa]

If you have not done any service work or handled a soldering iron, then not you.

Service techs are hard to find, so you might have to send it to a service center.

I don't know how hard it is to get to these components as they never issue service manuals. I'm going to guess that assembly fixing the problem and reassembly will be 2 to 3 hours. Rates will be around $75 to $100 per hour I expect.

With those rates I would look for new unit: http://www.accessories4less.com/make-a-store/category/avreceiver/home-audio/receivers-amps/home-theater-receivers/1.html