Another Yamaha CR-2020 story!

agger

more Pioneers :-)
Yes, things happen! There was a CR-2020 on ebay for 100 euros ($120). One channel dead and some idiot has painted the housing black. OK, waited 7 days and it was not sold :no: I offerd yesterday the seller 75 euros and he agreed to sell it (was that too much??).
I think I have looked for one like 2 years now for a reasonble price, but you need to be paicient and wait.... :banana:
So now its on the way. The good thing is, that it should be in original condition and nobody had attempt to repair it :thmbsp:
Ah, by the way, has someone of you guys a service manual on pdf to share? That would be nice.
 
Welcome to the CR-2020 club, agger! :banana:.

I don't have the service manual unfortunately but let me know if you need the owners manual and I'll email you it.
 
Now the baby received my home safely! It looks pretty ok, not much scratches and even the black housing does not look too bad. It has only a thin spray coating. But I think I will restore the original condition. I haven't plugged it in, maybe the weekend I find some time to go ahead.

Now here a picture:
 
Very nice agger...think it looks nice in black, but even better in maple, ash or cherry!
 
bully said:
Nice score. Hope it only needs minor repairs. Love my Yamaha gear!
One channel is bad, so it think the outputs are gone. But it was never repaired before, so a good point to start. :thmbsp:
--- I still I don't have a schematic, so if anyone has a PDF to share...
 
Don't be so sure, does the protection relay operate? Must else you would not know that one channel works. OK, deoxit in the rear panel switch that couples the pre-amp and main amp. More in the audio muting switch near the tuning knob.

At the back of the relay board on the left side is there heat discoloration? Might be advisable to do the Service Bulletin mods., That I can email to you.

Rob
 
The story continues...

Today I gave it a try, opened the cover and saw :sigh: what a rusty bastard:




Every screw is rusty, also on the rear. Also the wood cabinet looks as the unit has beed stored in a wet basement sitting on one side. :no:

After blowing some dust out I gave it a try and fired her up with the bulb-variac and ..... I heared a silent click :yes: , checked the offsets (15mV, 8mV), attached my test-speakers and the antenna, tuned in a station and everything works :banana: Both channels are OK, nothing defect, also all pots and switches work without scratches except the loudness pot.
I really hadn't expected that after opening the case. The bulbs are all out, but that's a minor problem. The right channel had been repaired before, the power transistors are replaced and the one pot on the board. But the unit worked for a hour without any problem :thmbsp:

So now I have a serious cleaning job in front of me and maybe I will reveneer the cabinet.

To be continued...
 
agger said:
Today I gave it a try, opened the cover and saw :sigh: what a rusty bastard:




Every screw is rusty, also on the rear. Also the wood cabinet looks as the unit has beed stored in a wet basement sitting on one side. :no:

After blowing some dust out I gave it a try and fired her up with the bulb-variac and ..... I heared a silent click :yes: , checked the offsets (15mV, 8mV), attached my test-speakers and the antenna, tuned in a station and everything works :banana: Both channels are OK, nothing defect, also all pots and switches work without scratches except the loudness pot.
I really hadn't expected that after opening the case. The bulbs are all out, but that's a minor problem. The right channel had been repaired before, the power transistors are replaced and the one pot on the board. But the unit worked for a hour without any problem :thmbsp:

So now I have a serious cleaning job in front of me and maybe I will reveneer the cabinet.

To be continued...

Agger -- That's DREADFUL. I feel for ya!!!!

-- Chris
 
I would said you need to do some cleaning. anyway, the unit should sound good. I have had CA2010 before and the sound was so good. especially in class A mode and after warming up. you will love it. when I had my CA2010, the user manual contained the circuit diagram. I am not sure if yours is the same. if yes, then you can just purchase a user manual off from ebay.
 
Too bad about that. IIRC, one of the big differences between NA and ROW markets is/was our requirement that transformers be canned. May or may not have made any difference, but certainly would have ended up looking better in the end (easier to paint). And, you don't need to purchase the OM with the schematic. Yamaha will let you download for free, here: http://www.yamaha.co.jp/manual/english/index.php Just type in CR-2020 and hit return. Good luck with it. A worthy and well made piece. The fact that it works while looking like it does is testimony to the quality.
 
Ah, they used different style transformers on the different markets???
I always tought only the voltages were different. Mine is a multi voltage unit.
Thanks about the OM-link. I have already downloaded it, but the schematic is nearly unreadable.
 
...update...

The last 2 days I got deeper in the CR-2020, changed all lythics on the amp and regulator boards, applied new heat spreader compound and cleaned the boards. What a wonder that the amp hadn't a problem with this :sigh:
See the difference:

Also the bias pots need to be changed, now its running fine at 10mV. Before both channel were around 95mV!

While poking around there, I found some scary solderjoints on the main supply board where the big caps are sitting.
Ok, I decided to pull that also out. The receiver is well packed, so its not easy to get acess to everything.
This board looks pretty carbonized around the power resistors. Someone else was in there before and resolderd them with some wires, the pcb tracks were gone.
The worst one is the resistor on the photo in the circle. I want to change it to a higher rated part and put some standoff from the pcb. But there is no print on it, my meter shows 31 Ohms. So ist it 33 Ohms??
So who can tell me, what the correct value is?
And are any service bulletins out there which also could be done while I have everythin appart?

 
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