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Yamaha CR-2020 Power Board & Electrolytic Cap. Board Kits?

RawWattage

RawWattage

New Member
Hello all,

Been rehabilitating the old YamaHamma as best I can but these boards are just falling apart. I know these components are famous time-bombs. Lets say I had brand new boards and all the upgraded components, would any body be interested in buying these as a do-it-yourself kit? Reasonably priced of course. I figure if I'm going to do the work in designing and ordering for myself I might as well get a sh*t load for the save-a-homie foundation.
Wad'ya think?
 
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Update:

Waiting on quotes from a few companies to produce the board. A couple in China and one in Europe I think. Hopefully this wont be too much of a hassle, the visual of all the track repairs on the bottom of this thing makes me uncomfortable. It looks like robot puke.
 
If I were doing new boards, I would make some changes so that better/larger heatsinks could be used for the two hot transistors on the PS. There is plenty of real estate freed up by using modern caps. Of course that's a different project than a photocopied replacement board...
 
I used Osh Park for PCB's. Good quality . and the boards are Purple ! kinda kool looking.

These are for a modification to a CRT Projector, Marquee 9500LC.

12072234653_1c8a3174c2_b.jpg
 
I agree with throwing some better heatsinks on. Id also like to move all the smaller components out from underneath that board so they can breathe. I drew up a 3x3 add-on board to mount on a bridge connected to the two topside mounting screws. It holds the two transistors horizontally (larger finned heatsinks face up) and the 33&22ohm 3watters mentioned in the SB. Just a matter of running wires to their respective points.

Aweful lot of work, but I'm in love with this damn stereo and I'd like to enjoy it 'till I'm 6 feet under.

Have not heard anything yet about the reproduction boards. Will check out Osh Park, I do like the purple.
 
Interesting idea. I have never worked on a piece of equipment with such fragile solder pads as my 2020.
 
So.....as im going through mapping out the board on eagle, i find this friggin trace that just goes nowhere. WTF. Is there some purpose for this or am i justified in laughing my ass off?
 

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If it truly goes nowhere (I cant tell from the picture) then you can leave it out. The boards were hand drawn with tape and Xacto knives so changes were not always easy. If it did no harm it could have been left in.
 
DRecovery said:
If it truly goes nowhere (I cant tell from the picture) then you can leave it out. The boards were hand drawn with tape and Xacto knives so changes were not always easy. If it did no harm it could have been left in.
Click to expand...
I do apologize to those hard workers. I imagine that job really sucked without computer aid, something i did not think about.
 
It's a mini antenna thats used to tune in extra awesomeness!

Still waiting on numbers for production. Best I've got so far is $45 per board + components that I have not had time to shop completely.

Been doing some thinking, and rather than sell these things im just going to make sure everything works proper and upload the gerber file for whoever wants it.
 
I'm having trouble with one of those at the moment. I can't tell if it's an intermittent trace or a transistor going bad?
 
Oh.... I just purchased a CR-2020 for my neighbors who want a decent vintage jewel in their living room, and I promised them to service it duly to ensure long term operation (if such thing is possible with vintage gear).

So I would be interested in your boards ! I would like to fit Nichicon KG Super Through with solder lugs in it. Any change you would have the sleeve sized holes in the PCB for it?
 
Oilmaster said:
Oh.... I just purchased a CR-2020 for my neighbors who want a decent vintage jewel in their living room, and I promised them to service it duly to ensure long term operation (if such thing is possible with vintage gear).

So I would be interested in your boards ! I would like to fit Nichicon KG Super Through with solder lugs in it. Any change you would have the sleeve sized holes in the PCB for it?
Click to expand...

I would rather have the caps separate. No point in having all that empty real estate at $5 a square inch..
 
I bought the 2020 new at Thieves audio in New Orleans a few years back. One on display had the clear case to show the reach rods from knobs to mainboard. I ended up trading for some GAS equipment due to my low paying job at the time...

Good luck on the project. Considering what I paid new in 1985 or so, the cost of stuffing new boards could get interesting?
 
Just working on my recap list, and discovered that at the PSU board:

1) C719 (TR704 base decoupling) is in reality a 12nF/50V mylar cap instead of 10uF/35V electrolytic cap as service manual indicates

2) C740 (buffer cap at emitter of relay driving transistor TR702) is not installed (it probably caused a too high current through TR702 when switching on)
 
Would these boards also work on a CR-1020 as there are plenty of those about? I also toyed with the idea of making a whole new PCB for mine.
 
Another good improvement (which Yamaha could have done already at the time) would be to use a 4-pole Omron relay instead of the current 2-pole relay. Sony gear was full of it. The tracks under the relay allow for it, giving a much lower resistive path, and much longer lifespan. Shame shame shame.
 
Oilmaster said:
Another good improvement (which Yamaha could have done already at the time) would be to use a 4-pole Omron relay instead of the current 2-pole relay. Sony gear was full of it. The tracks under the relay allow for it, giving a much lower resistive path, and much longer lifespan. Shame shame shame.
Click to expand...

I was looking at replacing mine with one of these, I know it's DPDT but nice to know you can get one:

http://au.rs-online.com/web/p/non-l...9322D302D44433132267374613D4C5932304443313226

I have also been trying to work up a list of common replacement transistors for the CR-1020 which would probably work for the CR-2020 as well, it would be a great resource.

Here is what I have so far and hopefully people will have some better suggestions or be able to weed out any that won't work:

2SC1890 = BC168, BC639, 2N5832, KT666A9

2SA844 = KSA1013, BC556 - A

2SC1918 = KSC1845, 2sc2240, , BC168

2SD234 = TIP31A

2SD400 = NTE382

2SC1213A = KSC2383YTA

2SA673A = BC327 - A

2SB544 = NTE294, KTA1273
 
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