CR 800 power switch

moromete

New Member
Hello,

This is my first post in Yamaha section.
I got as student, from my father ,his old receiver CR 800.
I still have it and my intention is to use it daily and use the 7.1 system just for movies. The problem is the power switch is arching.
Can you please tell me where to find a replacement?

Daniel
 
I assume the switch only arch's once at power on/off not continuously.
The snubber capacitor (2? x 0.0033uf+120ohms) next to the switch is included to suppress the arch. Suggest you replace that first.
 
Thanks for reply! The European version has no snubber cap+resistor in series. Strange...
I meant a modern replacement because I see in my other Yamaha CR 600 that has a nicer switch , from Noble.

Daniel
 
Thanks for reply! The European version has no snubber cap+resistor in series. Strange...
I meant a modern replacement because I see in my other Yamaha CR 600 that has a nicer switch , from Noble.

Daniel
They all have snubbers. I think you can modify a different switch to fit in. Try tv5 Alps maybe.
 
Just to ease my curiosity checked all vintage amps /receivers today.
CR 800 and CR 600 European version with DIN connectors has no snubber cap+resistor . Same thing is shown in power supply schematic.
Sansui G8000 and Kenwood KR 9600 have this package . In Kenwood case , looks like an afterthought, and not properly isolated.

Daniel
 
CR 800 and CR 600 European version with DIN connectors has no snubber cap+resistor .
Yep, confirm, the sm shows no snubber for the EU models, snubbers fitted to all other models US, SA, General AU. Seems like you have a choice like finding
a replacement switch or add the 2 snubber caps.
 
Yep, confirm, the sm shows no snubber for the EU models, snubbers fitted to all other models US, SA, General AU. Seems like you have a choice like finding
a replacement switch or add the 2 snubber caps.
If its already arcing. Its to late for snubber. Damage to switch contacts has already happened. Pitting and arc flashing = burnt contacts.
 
Without a snubber, arching can happen at anytime, just depends where in the cycle the power is connected/interrupted. If the voltage is high enough
then arching will occur. Since it's a vintage piece without a snobber, it's been arching all it's life so contacts can't be healthy, in anycase I would still go
with a snubber, new switch or not.
 
Just because my soldering iron don't get hot enough to take switch out, I went over the moon to fix the switch. I used a small cylindrical lapping stone for watch makers to polish contacts. My father advice in restoring relay an power contacts was after polish to use dental silver mercury alloy , brushed and leave to set 3 min.
Reassembled and ... no arching anymore.
Thanks all for your advices . Ill get a snubber cap on this switch asap.

Daniel
 
So what happens when it's arcing?
How reliable are those old snubbers? I found bulgy snubbers in Sonys but in Yamahas they look neat.
 
So what happens when it's arcing?
How reliable are those old snubbers? I found bulgy snubbers in Sonys but in Yamahas they look neat.
Might come down to design ie, C versus R+C maybe. With no snubber it will arc "all the time", any switch bounce
will trigger arcing. I must be missing something, seems like a no brainer.
 
I guess it's rather aftermath of arcing and not arcing itself that is the problem.
Below snubbers taken out of two Sonys STR-6065
I noticed some are literally a resistor and capacitor in series, some are a capacitor of a high resistance, the vintage like these are the latter.
snubbersbulged.jpg
 
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I noticed basing on my units all bought in Europe
  • if there are AC outlets at the back then there is a snubber 0.033uF 120R at the power switch
  • with no AC outlets both power wires go through power switch and there's no snubber(s) installed
Also I can hear that the snubber did its job through years.
 
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