Yamaha CR-600 different board numbers??

daveyh

AK Subscriber
Subscriber
I have a Yamaha CR-600 that has a power supply board number of 64602. It is a different number than the one in the service manual I downloaded from the AK forum. In fact all the board numbers are different than the SM I have. I tried to find one online but can not seem to locate it. Does someone have any idea if Yamaha made two different designs? They must have because I have one. Where can I get a SM so I can fix this puppy. No click in relay.
 
I have a Yamaha CR-600 that has a power supply board number of 64602. It is a different number than the one in the service manual I downloaded from the AK forum. In fact all the board numbers are different than the SM I have. I tried to find one online but can not seem to locate it. Does someone have any idea if Yamaha made two different designs? They must have because I have one. Where can I get a SM so I can fix this puppy. No click in relay.
Most likely the info you need is in a long lost service bulletin.
Check your DC offset at the output of the amplifiers before the relay ?
 
Most likely the info you need is in a long lost service bulletin.
Check your DC offset at the output of the amplifiers before the relay ?

How do I know what it is suppose to be without a manual? Can you tell me how to do it?
 
How do I know what it is suppose to be without a manual

Just checking for rail voltage. If you have rail at the speakers - the protect circuit is working.If you have closer to zero volts +/- 50mv then the protect circuit is malfunctioning.
Post a photo of the amplifier board(s).And I'll show you where to measure the DC offset.
 
Just checking for rail voltage. If you have rail at the speakers - the protect circuit is working.If you have closer to zero volts +/- 50mv then the protect circuit is malfunctioning.
Post a photo of the amplifier board(s).And I'll show you where to measure the DC offset.

I have no voltage in the speaker terminals.

This is a learning process for me and I am by no means a certified tech.

I don't know if all I have done so far is correct but here and some things I have done with this unit:

I have recapped the power supply and the driver board. I also do this on all the units I work on. I like to solder. :) I replaced the 2sc458 transistors in the driver board with 2sc2240's. I read another forum on AK that said they were OK to use. I did check the orientation with my transistor checker. I just turned the 2240's around. Hope I did it right. Didn't effect anything that I could see. I am running it on a DBT. The 75 watt lamp is very, very dim. I also pulled and checked the 4 outputs transistors which were all fine. I checked all the other smaller transistors and all were fine. On the power supply board I found a resistor on HW4052 that was open. It looked like a 23 K ohm? It was hard to see the bands and I can't find it in the SM. So I guessed at it. It looked to be red, orange, orange, silver. I tied a 22kohm and a 1Kohm together and replaced it but still no relay. I also looked for cracked solder joints in the power supply and driver board. I did re-flow the power supply board.

Ready when you are to go further. Thanks!
 
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I have no voltage in the speaker terminals.

This is a learning process for me and I am by no means a certified tech.

I don't know if all I have done so far is correct but here and some things I have done with this unit:

I have recapped the power supply and the driver board. I also do this on all the units I work on. I like to solder. :) I replaced the 2sc458 transistors in the driver board with 2sc2240's. I read another forum on AK that said they were OK to use. I did check the orientation with my transistor checker. I just turned the 2240's around. Hope I did it right. Didn't effect anything that I could see. I am running it on a DBT. The 75 watt lamp is very, very dim. I also pulled and checked the 4 outputs transistors which were all fine. I checked all the other smaller transistors and all were fine. On the power supply board I found a resistor on HW4052 that was open. It looked like a 23 K ohm? It was hard to see the bands and I can't find it in the SM. So I guessed at it. It looked to be red, orange, orange, silver. I tied a 22kohm and a 1Kohm together and replaced it but still no relay. I also looked for cracked solder joints in the power supply and driver board. I did re-flow the power supply board.

Ready when you are to go further. Thanks!

I need to see the component side of the actual amplifier. Not the power supply.
 
Look the amplifier board over real good for two test points. (two metal pins should be labeled TP3 and TP4.)
Connect your meters black test lead to the metal chassis(ground). With the red test lead , check the for DC voltage at TP3 ,then at TP4. Even though the board layouts may be slightly different the test points should be the same.
Post the voltages at those two points.
The amplifier board will be closest to the large heatsink that the large output tranistors are secured to.
 
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I found the points TP3 and TP4.

With my meter set on VDC auto and black lead to chassis (ground) and red lead to test point my readings are:

TP3 = -100.4 mv
TP4 = 8.3 mv

Is this what you are looking for or do I need to set my meter at a different setting.
 
I found the points TP3 and TP4.

With my meter set on VDC auto and black lead to chassis (ground) and red lead to test point my readings are:

TP3 = -100.4 mv
TP4 = 8.3 mv

Is this what you are looking for or do I need to set my meter at a different setting.

That's good news. The 100mv should adjust down to closer to zero. Adjusting it now won't solve the problem.
It appears you have a power supply / protect circuit problem.
 
Looked on page 29 of the SM I have on how to adjust them and adjusted them down to around zero. Just changed the lamps because they were not working. The lamps light now. I had some 12V wire lamps I ordered for my other Yamaha CR-820. The lamps light now. I did not replace the two BP caps on the amp board because I was out of them. But I did pull and check them. They seems to be OK. I have a cap checker on my meter.

Here's a pic of the board.
 
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Looked on page 29 of the SM I have on how to adjust them and adjusted them down to around zero. Just changed the lamps because they were not working. The lamps light now. I had some 12V wire lamps I ordered for my other Yamaha CR-820. The lamps light now. I did not replace the two BP caps on the amp board because I was out of them. But I did pull and check them. They seems to be OK. I have a cap checker on my meter.

Here's a pic of the board.

So have you replaced any caps on the driver board ( the board with the relay in your photo?)
 
Need a closer ,clearer photo of the 3 small caps below the relay in the photo.

Have they been replaced ? Is there and N or NP silkscreened on the board next to these two caps?

N,NP,BP = non polar/bipolar
 

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If you take a look on my list of fuse resistors used by YAMAHA HW405220 is fuse resistor of 220 ohm 1/2 W

This may be explain why
 
I have replaced all the caps except the ones in the picture marked with arrows. I did check them and they seem to be OK. But I went pulled them again and checked the larger black 16V 47uf caps again just to be sure and one reads 68.9uf both ways and the other 46.6uf both ways. Do I have a bad one? Can they be replaced with regular caps?
 
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Is one suppose to read 68.9 if it is a 47uf cap? Could this be the problem of the protection relay not clicking in? I was going to order some more caps from mouser anyway and replace them. Need to do it today.
 
If you take a look on my list of fuse resistors used by YAMAHA HW405220 is fuse resistor of 220 ohm 1/2 W

This may be explain why

On my post #5, I posted. "On the power supply board I found a resistor on HW4052 that was open". I meant HW40522. I forgot a 2 on the end.
 
Need a closer ,clearer photo of the 3 small caps below the relay in the photo.

Have they been replaced ? Is there and N or NP silkscreened on the board next to these two caps?

N,NP,BP = non polar/bipolar

I will get this for you. Sorry for some reason your post is lagging behind and I just now seen it.
 
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