Yamaha Ca-2010 Relay Ticking Issue

[Bluhn321]

Hi everyone,

I have a Yamaha Ca-2010 that has an issue. When you first turn it on with the volume at zero both relays click on and it seems okay. However as soon as you turn the volume up both relays start to click on and off. One strange thing I noticed, if its any help, that if you turn off the pre-out under the audio muting switch both relays will click on and stay on if you turn up the volume.

When its stable with the volume at zero I measured DC output and both channels only had a few mV so the amp section seems fine.

UPDATE-

The relays will click when powered no matter what volume or setting. I also notice that the power relay has an arc each time it clicks so something is drawing current.

Any help would be greatly appreciated!

 

[willyrover]

If this is an all original 2010, I would say with 99.9% certainty that there are bad capacitors on the power supply board. There are several caps that are very close to very hot components. (lower right in photo, bottom of unit)

 

[avionic]

Possibly bad solder connections in the regulated 12 vdc supply source for the relays as well as caps.Or a misbehaving regulator transistor.

 

[Bluhn321]

Alright so I did find a cracked solder connection on a regulator and reflowed it. Its still clicking but now its back to how it was before the update. So when the volume is turned up they start clicking and if you turn off the pre-out under the audio muting switch both relays will click on and stay on if you turn up the volume.

Another thing I found was that if you switch it into class A mode only the relay on the bottom clicks on. Not the power relay.

 

[avionic]

The top relay is for class A switching. The bottom side relay is the protect relay.

 

[avionic]

So when the volume is turned up they start clicking and if you turn off the pre-out under the audio muting switch both relays will click on and stay on if you turn up the volume.

Sounds like a pre-amp issue. Need to check your power supply voltages that feed the pre - amp section of the 2010.

 

[avionic]

As willy has already stated theres probably 3-4 caps in the power supply. Maybe more . That usually exhibit overheating with shrunken down plastic labels on the electrolytic capacitors. I'd re-cap the whole enchilada. (power supply board)
Unless its already been addressed.

 

[Bluhn321]

Here is what I got from the power supply pins. Its hard to read the schematics so I can't tell if they are ok.
+b3, 13.7v before relay clicks on and 11.7v after
C, 13.8v before relay clicks on and only 215mV after
-b1, -73v
-b2, -30.5v
E, 0v
+b2, 47v before and 48v after
+b1, 72v

I'd re-cap the whole enchilada

That's what I'm planning on doing. While I'm at it should I recap anything else? Everything is stock as of now.

 

[Bluhn321]

Here is a picture of the power supply. There are some caps with shrunk labels.

 

[avionic]

Those two violet ones are in the protect relay circuit. Your problem may very well disappear with a recap. Pay attention to polarity. I think there is like at least 4 non-polar/bipolar on that board. Use either nichicon EP or ES. I'd use the "EP series" high temp caps. It tends to get a little toasty around those power transistors.

 

[Oldsansui441]

+1 on the power supply recap, some of your caps look pretty average (the plastic sleeves have shrunk). I would do the whole thing as well, these are actually pretty easy to work on compared to other units.

 

[willyrover]

I may not be reading the schematic correctly, but it looks like the Pre-Out Off switch is controlling a relay. The relay closes when the unit is powered on and opens when powered off OR when the Pre-Out Off switch is activated.

There are a bunch of relay coils that are powered from the same part of the power supply board. Less load on the relay coil circuit could explain why the relays aren't chattering when Pre Out-Off is activated.

Recap the board, and reassess.

 

[avionic]

I may not be reading the schematic correctly, but it looks like the Pre-Out Off switch is controlling a relay.

There is also 2 each small RL reed relays.

 

[Bluhn321]

Just ordered the caps so it'll be a few days before they get here.

 

[Bluhn321]

So here's an update. Got the caps in but it still has the same problem that if you turn up the volume the relay clicks off. However it no longer ticks on and off and just stays off until your turn the amp off.

Everything else is the same.

 

[Bluhn321]

Could the problem be in the preamp section?

 

[avionic]

To me it sounds like it is the pre-amp acting up. See post # 6.........

 

[avionic]

To me it sounds like it is the pre-amp acting up. See post # 6.........

Or the power supply for the pre-amp.

 

[avionic]

Did you recap the entire PS board ?

 

[HVHiFI]

Check the voltage on the coil of the relay. I've seen many regulators go bad that are feeding power to the relay itself and they will present the symptoms your seeing. Leave your meter on the coil and increase the volume to see if you get a drop when the relay opens.