Yamaha CR-1020 power supply recap

PatA

Super Member
I'm pretty positive Merrylander started a thread on this topic, but I lost patience in searching for it, bad I know! Seems to me that he also explained how he accessed the bottom of the board, so I apologize if this is redundant. I removed the chassis side rail, unbolted the transformer and moved it aside as far as the wiring would allow. I then unbolted the brackets that hold both parts of the power supply, I'm able to flip the board over pretty easily. I have my cap list put together, and I also want to replace the power transistors, I believe they are TR712 and TR715, both are 2SD234R. The OnSemi site crosses these to TIP31G or TIP31AG. The TIP31G is rated at 40 volts, TIP31AG is rated at 60 volts. Is the 40 volt rating sufficient? Or do I need to use the 60 volt rated transistor? Thanks all.
 

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No use a TIP41C as Yamaha recommended replacing those two with 2SD525 but they are no longer available. Oops, this is a CR-1020 then use the TIP31AGs because the initial voltage to hit the transistors is in excess of 40V.

The title of that thread is CR-2020 Service Bulletin Mods.
 
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PatA, I have a CR-1020 that I would like to do as well. Is it possible to post the list and your source(s) for the parts. I hope somehow to return the favour. There's probably a lot of Yamaha fans out there would like to do this too.....not that it's absolutely needed but this is a hobby...right! Thanks...
 
Here it is;
Here is what’s on the board;
2. 25 volt, 3.3uF
7. 16 volt, 10uF
2. 10 volt, 100uF
1. 25 volt, 4.7uF
2. 25 volt, 22uF
2. 25 volt, 47uF
1. 16 volt, 47uF
2. 35 volt, 100uF
3. 35 volt, 10uF
1. 16 volt, 100uF
2. 6.3 volt, 47uF
1. 35 volt, 1000uF
2. 25 volt, 220uF
1. 25 volt, 100uF
1. 25 volt, 10uF

Here is what I’m planning on ordering;
11. 647-UVZ1H100MDD
6. 647-UVZ1H101MPD
5. 647-UVZ1H470MED
2. 647-UVZ1H3R3MDD
1. 647-UVZ1H4R7MDD
2. 647-UVZ1H220MDD
1. 647-UVZ1H102MHD
2. 647-UVZ1H221MPD
2. TIP31AG, (transistors)

These are all rated at 50 volts, that’s kind of the way Mouser wants to supply them and there won’t be any size issue. They are Nichicon 105 degree UVZ series caps, which are more or less like OEM. I’ve had good luck with these, but there are higher quality caps available. Total cost is $7.60 plus shipping.
 
Just finished my order, Mouser back ordered the 50 volt 1000uF cap so I ordered that one in 35 volt. The part number is; 647-UVZ1V102MHD. Everything else was in stock.
 
Putting a 50 volt cap where a 6.3 is called for may not be the best idea. I understand that an electrolytic of to high a voltage will not 'form' properly.
 
Thanks PatA and Rob, I might wait until your project is finished before I jump into this. It would be fantastic if you could post your progress as you get into it. I'm a rookie and don't want to destroy something that I can't fix. Thanks in advance for all the help.
 
Putting a 50 volt cap where a 6.3 is called for may not be the best idea. I understand that an electrolytic of to high a voltage will not 'form' properly.

Yeah, my bad, I needed to consider that. To much material in a 50 volt cap for just 6.3 volts, thanks Merrylander. I ordered 16 volt caps to replace these, they are part number; 647-UVZ1C470MDD.
 
Hello PatA what part number on your list was replaced with this part number 647-UVZ1C470MDD ? And what is the part number for the 50 volt 1000uF cap that was back ordered ? If that all makes any sense. Thanks. I am very new at this hobby I hope you understand my silly questions. I want to use your parts list to rebuild my 1020 and ordering part is pretty overwhelming if you know what I mean. Or maybe a revised list if you have it . Thanks again .
 
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Use Nichicon " PW"'s instead of "VZ". Nothing wrong with the VZ's but PW's are usually available.
 
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