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Yamaha CA-2010 possible restoration

Oldsansui441

Oldsansui441

Super Member
Hi, l have recently purchased a CA-2010 that is not working. Has 2 blown main amp fuses and the main A/C power supply fuse is also blown.
I have just disassembled the main amps and have found two shorted output transistors on one channel. No doubt the drivers will be shorted also, at the least.

Since l am already in there instead of just repairing this unit l may as well recap, replace fusible resistors if necessary, trimmers, necessary diodes (if any vd1212) and relays.

This unit doesn't have any 2sc458 transistors, are there any other transistors in the CA-2010 that usually require pre-emptive replacement. When l do other amps/receivers l can usually identifiy troublesome transistor numbers but l am not familiar with the 2010 so just wanted to check with you Yamaha gurus before l make a parts list :).

Here are the numbers

2SA673A
2SA777
2SA872
2SB537
2SB566ANS
2SC1213A
2SC1509
2SC1775
2SC1918
2SD381
2SD476ANS
2SD526

Any help appreciated, cheers.
 
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I have decided to do a full recap on this 2010, excluding main filter caps as these test within spec. It will also be getting new outputs MJ21193G and 94G's and new Fairchild driver transistors.

I have a very poor schematic and l am trying to substitute the 4.7ohm 230mA fusible resistors on the main amp +B1 and -B1 supplies. Because l can't read the voltages on my schematic l cannot convert the 230mA rating into a wattage rating for the replacements. When l placed my mouser order l ordered some 1/4 and 1/2 watt fusibles in 4.7ohm. Does anyone know if the 1/2 watt fusibles would suit here?

If l get a chance l will post up some photos of the project in a few days.

Regards.
 
Thanks for that avionic, for some reason l thought l needed voltage for a calculation. Cheers, much appreciated :thumbsup:.
In regards to the transistors do you normally replace any of these based on past experience. I am thinking of replacing the regulators on the power supply as a precaution.
 
I'd be interested in how you go with the refurb. I've got one to do in about 4 weeks time. Any hints appreiciated.
I'm practicing on a CA-1010.

Regarding transistors, some people replace "all" outhouse/dunny shapped. Have not seen the justification for this.
Sure the C458LG and the C1345. No plan to change transistors on the CA-1010, guess I'll learn.

Also, is there an issue with the 1S1555 diodes? Noticed that some people do a pre-emptive replacement with 1N4148.
People have reported problems with VD1212, so it gets binned.
 
Hi, thanks for your interest, there are surprisingly few threads on the CA-2010. Yes l have read about the 2SC458 replacements but the 2010 has none of these. It does have some outhouse shaped transistors but no mention of these numbers being prone to failure.
I have checked ALL diodes in this unit and all are fine, no VD1212's present either. All fusibles were within spec except 4 on the main amp boards which l have replacements for.

This amp is surprisingly easy to work on, the board traces are excellent, l have completed approx 100 soldered joints so far and zero sign of any pads or traces wanting to lift.
One thing l would highly recommend is to desolder the necessary wires to completely remove the main amp boards and heatsinks, l have noticed that most people don't generally do this but l found for a little extra work it makes working on the amp boards and main outputs a breeze.
I will also be replacing the two relays with new Omrons and the trim pots with bourns single turn, couldn't get multi turns with the correct orientation, even the single turns are very hard to source with side adjustment.

I should be able to finish this up by the end of the week and will post up some more info, Cheers.
 
First i just want to say Avionic knows and i don't. That being said, This is good advice for any repair /restore project. Get the original problem resolved before you dive face first into the recap. Its easier to keep track of a possible problem. If you do it all at once you don't know what you solved and it makes looking for mistakes much more difficult. Just my 2c Good luck! its a nice piece!
 
Oh yes nj pheonix, that is good advice, l have repaired many amps/receivers ALL not working and l generally always repair original problem before any restoration work, however in this case it is not exactly a 10 min job to replace outputs and drivers and re-assemble just to test operation, that is why l am doing everthing while l am in there once only. Have faith, what is the worst that can happen :rolleyes:.
Thanks for your support!
 
mbz said:
Agree 100%. These amps are fully discrete, back yourself.
Worst case scenario is a dead transformer so do a variac p-on and check voltages.
Click to expand...

Thanks for that mbz :thumbsup:. Sorry didn't notice on your first post that you are a fellow Victorian, hi from up the road!
 
The big beast is alive, first powered up without amp fuses in place so l could check power supply voltages and all were spot on. Refitted main amp fuses and checked and set both biases, then DC offset. Damn these run hot at 300mV in class A, surely it would be a good idea to use this feature sparingly for the longevity of the unit?

Singing away nicely in living room at the moment, :). I will post up some photos when l get more time as l know some of you may say "it didn't happen'' haha, and l know how much you guys and girls here like photos.
 
Oldsansui441 said:
Damn these run hot at 300mV in class A, surely it would be a good idea to use this feature sparingly for the longevity of the unit?
Click to expand...
My philosophy on my CA-800/-1000 is to use class A all the time, except on background "noise" duties. The ripple will be tough
on those Nichi KG type 1's(?) and you may need to replace them a little earlier, but that's a small price. To be honest I don't
really like the KG's, they were upstaged by KW's in smaller gear. I'm trying United Chemicon and boutique (Mundorf) in my
next projects.
 
mbz said:
My philosophy on my CA-800/-1000 is to use class A all the time, except on background "noise" duties. The ripple will be tough
on those Nichi KG type 1's(?) and you may need to replace them a little earlier, but that's a small price. To be honest I don't
really like the KG's, they were upstaged by KW's in smaller gear. I'm trying United Chemicon and boutique (Mundorf) in my
next projects.
Click to expand...

So you use class A frequently then by the sounds of it. I guess Yamaha wouldn't have designed these amps to run so hot if it caused reliability issues. Why don't you like the Nichicon KG's? l have used before and think they are a good quality filter cap but l know there is certainly better and much more expensive caps out there. Yes United Chemicon seem to make some nice caps, l have used Vishay filter caps before also.
 
I run mine in Class A for hours...but i admit it makes me nervous...i rested the milk thermo on the top on Friday night and it hits 70c. It must be real host down on those transistors and heat sinks.
 
Jpete9 said:
I run mine in Class A for hours...but i admit it makes me nervous
Click to expand...

Think it would make me nervous also, makes me wonder if it would ever get hot enough to slightly distort the wood cabinet.


Jpete9 said:
i rested the milk thermo on the top on Friday night and it hits 70c. It must be real host down on those transistors and heat sinks
Click to expand...

That temp doesn't surprise me at all going by the heat coming off the heatsinks l felt. You are right, the components really have to take a lot.
 
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