recapping vs not recapping

I will go for GP Nichicon PW and PM series, they are higher ripple than audio caps if it matters, and rated at 5000hrs.
 
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Myself, I just use standard metal film, maybe 1/2W to keep the temp down. Fusible resistors were briefly all the rage but are not used much any more. They are all over the CR-1000 but the next generation (xx20) used very few, IIRC. Modern Yamahas have none that I can think of.
If all resistors marked with the zigzag are fusible then there are like 300 of them.
 
I will go for GP Nichicon PW and PM series, they are higher ripple than audio caps if it matters, and rated at 5000hrs

Great choice if you are referring to the power supply. PW's are actually designed for switch mode power supplies and will do well here also.
 
Before this turns into the "great capacitor shoot-out of 2017", there are other things to consider. Yes, I do gravitate toward Nichicon, Panasonic and Elna caps when undertaking a project and buy them from "reputable" dealers like Mouser, DigiKey and Parts Connexion (rather than buying the cheap Chi-Fi "knock-offs" on Eprey), but there are lots of other things going on here--diodes and transistors can "leak", resistors become heat-stressed and drift out of spec, etc--pretty much all components "age".

Modern caps are generally smaller in size for any given value, and are also available in much tighter tolerances (1%, 5% vs the old 20% typical standard), as are a lot of the other components. Performance parameters of individual components or the unit as a whole can be measured on the bench with the correct test equipment, but sound is up to the ears of the beholder. Maybe you just prefer the "sound" of the aging components vs the tighter-spec modern components, or maybe there are enough out of spec old components remaining that the new replacements have enhanced the audible effects of their flaws. I have had the opportunity to A/B identical units--one fully restored (not modified) vs one that had been untouched for 40 years--the difference was dramatic--it's just a a matter of which you prefer in terms of sound--both were fully operational, but the sonics were dramatically different.
 
Myself, I just use standard metal film, maybe 1/2W to keep the temp down. Fusible resistors were briefly all the rage but are not used much any more. They are all over the CR-1000 but the next generation (xx20) used very few, IIRC. Modern Yamahas have none that I can think of.
I have a CR1000 in line for overhaul and would like to start gathering parts for it. Wanting to know how many fusible resistors and of what wattage or even part numbers from Mouser to order to replace them all ? I want to replace the bias pots to multi turn . I think there are like six of those. Thanks for any information you may share.
 
res2.jpg I have measured some resistors randomly. If I read them right most of them are ok within specs. I found the ones with stripes orange/white/orange/gold are off. Should they be 39k? I mean the one on the left in the pic below. And the one on the right 1.6k? Also are they carbon or metal, and can you tell if they are fusible?
res1.jpg
 
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Your first one has issues.
I think you were right. I had problem with volume pot. I lost one channel, I turned left and right energetically, I got back the lost channel and also both channels are louder now and with more bass. :)
 
I would check all the white ones. The fusible resistors will be designated FRxxx instead of just Rxxx.
I just measured most of the white ones and they are scarily within specs, it's like spot on what is written on them I had on multimeter.
 
Should they be 39k? I mean the one on the left in the pic below. And the one on the right 1.6k? Also are they carbon or metal, and can you tell if they are fusible?

The one on the left looks like 39K 5% (carbon film?) - and looks cracked.
The one on the right looks like 18K 5% (carbon film?) - looks OK.

Neither is fusable.
 
The one on the left looks like 39K 5% (carbon film?) - and looks cracked.
The one on the right looks like 18K 5% (carbon film?) - looks OK.

Neither is fusable.
OK, great. So are the fusible always mounted away from the pcb and usually bigger in size with specs written on them? Because those are actually true to original specs, like new really, not even in +-5% but in 1% I would say. Must measure all though.
I measure them in circuit.
 
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The one on the left looks like 39K 5% (carbon film?) - and looks cracked.
The one on the right looks like 18K 5% (carbon film?) - looks OK.

Neither is fusable.

I think that's just some dirt or a cobweb, the "crack" appears to extend across the gap and touch the next component.

To get a good measurement on a resistor, you have to unsolder one end.
 
Time you read this http://audiokarma.org/forums/index.php?threads/fuse-resistors-the-wheres-whys-and-hows.430439/

Hopefully to help you become more familiar with fuse resistors - above thread no use for locating Yamaha fuse resistors, but Sansui used them quite a lot so the documentation and discussion in the thread linked is invaluable to us Sansui freaks. :)

Note well that they are intended to be a safety device. However very few people find and use new fuse resistors, as they seem to be rather unreliable especially with age. Most including me, replace them with same wattage metal film replacements.

The 'same wattage' bit is important - you want them to fail if there is a fault condition, like too much current somewhere due to a failed semiconductor for example. Increasing the wattage will make them last longer under these fault conditions, potentially causing more damage.
 
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View attachment 857450 I have measured some resistors randomly. If I read them right most of them are ok within specs. I found the ones with stripes orange/white/orange/gold are off. Should they be 39k? I mean the one on the left in the pic below. And the one on the right 1.6k? Also are they carbon or metal, and can you tell if they are fusible?
View attachment 857420

Some time you have to remove the resistor to get the actual reading as it may be in parallel with other resistors etc.

When and if I replace resistors I use metal film unless it calls for something else.
 
Time you read this http://audiokarma.org/forums/index.php?threads/fuse-resistors-the-wheres-whys-and-hows.430439/

Hopefully to help you become more familiar with fuse resistors - above thread no use for locating Yamaha fuse resistors, but Sansui used them quite a lot so the documentation and discussion in the thread linked is invaluable to us Sansui freaks. :)

Note well that they are intended to be a safety device. However very few people find and use new fuse resistors, as they seem to be rather unreliable especially with age. Most including me, replace them with same wattage metal film replacements.

The 'same wattage' bit is important - you want them to fail if there is a fault condition, like too much current somewhere due to a failed semiconductor for example. Increasing the wattage will make them last longer under these fault conditions, potentially causing more damage.

And metal film or metal oxide is desirable, as they're generally flameproof. You don't want one of them lighting off when it fails.
 
Thx for all info on fusible resistors. I checked most and they are true to specs.
Also I checked most caps on power board and the same. Only the 4 biggest caps were at 70% of specs, I replaced them. Others were spot on or above, e.g. the two 470uF 25v caps read, one spot on 470uF, the other 520uF, many caps were slightly above specs, also didn't see any eletrolyte spilled under them. The amp sounds great though there's some hissing in the background. I also replaced some higher risk transistors on power board. Soon will replace the two 10000uF filter capacitors, they read 7000uF each.
 
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