Yamaha CR-1020 Receiver Resto

[vitalsigns65]

Rob, you have a P/M

 

[vitalsigns65]

Hello There!

The parts I ordered are here, have the day off, and I am working on this receiver.

I just want to be certain before I proceed that the polarity of all the caps on the big cap board are correct.

Before I put resistors in I just want to verify that I have this right.

Anyone?

 

[vitalsigns65]

IT'S FIXED! IT'S FIXED! iT'S FIXED!



I AM SO HAPPY!
I AM SO HAPPY!
I AM SO HAPPY!

FOUND A TRACE THAT NEEDED ATTENTION!

THANK YOU TO EVERYONE WHO HELPED!
COULD NOT HAVE DONE IT WITHOUT YOU!

YOU KNOW WHO YOU ARE!

 

[vitalsigns65]

Seriously happy camper!



I FIRST ADJUSTED IDLE CURRENT TO
10 mv L & R


THEN I CHECKED THE BIAS
L- 5 mV
R- 12mV

SAME FOR A,B,C

I AM STARVING TO DEATH! I HAVEN'T EATEN A THING!
BEEN HERE ALL DAY WITH THIS, BUT MAN IT WAS WORTH IT!


GONNA GO EAT THE ASS OUT OF A DEAD RHINOCEROS!





AND YES, I DID TAKE MY MEDICATION TODAY!

 

[avionic]

Sweeeeet!!

 

[grillebilly]

who da man? :thmbsp:

 

[merrylander]

Good on You!

 

[vitalsigns65]

New "HAPPY" persona!

It's the next day and this recent triumph has inspired me towards a positive outlook.



Call me crazy, and I must be, but now I am seriously considering pulling the two PCB's surrounded by the heat sink assy. I believe the SM calls these the Main Boards.

Why, right?

Well, I can see some caps on those that I want to replace.

Any advice before I delve in?

Thanks for the kind replies regarding my victory, btw.

 

[avionic]

Take notes , or pictures before any parts removal. Note OEM cap polarities. Solder traces on those sheets are easily lifted (excessive heat from soldering should be avoided). The outputs transistors will need to be removed to access the foil side of the boards.Make sure the right transistors get put back in the right sockets. Do one board at a time, one component at a time.
Clean off the old thermal compound from heatsink/mica insulator & transistor and then apply fresh compound sparingly--all thats needed is a very thin coating on both sides of the mica insulators.

 

[brutal]

Glad you got it going. You were in the hands of two of the best Yamaha techs to be found. Rob and Dave are the bomb.

 

[vitalsigns65]

Glad you got it going. You were in the hands of two of the best Yamaha techs to be found. Rob and Dave are the bomb.

Amen to that!

I really do appreciate all the help and support!

Dave- you da man! I will heed the advice you've given to me and proceed with caution.

Been playing with the Sony XDR-F1HD and for those who may not know, this is a $100 HD FM Receiver.

I hooked it up to my superb roof antenna that is normally connected to my modded Pioneer TX-8500 ll .

All I can say is ~~WOW!!~~

This is way off topic, I know, but had to say it.

Peace

 

[vitalsigns65]

Take notes , or pictures before any parts removal. Note OEM cap polarities. Solder traces on those sheets are easily lifted (excessive heat from soldering should be avoided). The outputs transistors will need to be removed to access the foil side of the boards.Make sure the right transistors get put back in the right sockets. Do one board at a time, one component at a time.
Clean off the old thermal compound from heatsink/mica insulator & transistor and then apply fresh compound sparingly--all thats needed is a very thin coating on both sides of the mica insulators.

Good morning Dave,

I have an Aoyue 973+ and it's pretty good, digital read-out, one button rest mode, however... the cord to the iron is too short.

Damn the cost cutters!
:scratch2:

The temp display is in Celsius, and I use an indicated 425' C to do a fast in and out.

Am I running too hot, Dave ?

Best to you,

Jim in NY

 

[brutal]

Good morning Dave,

I have an Aoyue 973+ and it's pretty good, digital read-out, one button rest mode, however... the cord to the iron is too short.

Damn the cost cutters!
:scratch2:

The temp display is in Celsius, and I use an indicated 425' C to do a fast in and out.

Am I running too hot, Dave ?

Best to you,

Jim in NY

Yikes. That's really only appropriate for desoldering large lug filter caps or anything else with a large sink that needs a little extra heat. That's around 800*F

700*F is 372*C that's what you should be running for general work if you're desoldering old stuff and soldering with good eutectic (63/37) solder.

 

[vitalsigns65]

Yes I thought this may be the case. Must say though, it's never caused a problem for me, but in the interest of safety I will drop it down to your advised temp.

Thanks, Brutal

Jim

 

[vitalsigns65]

Pulled the Main Boards

I am back to working on the CR-1020, after enjoying it for a few days.

On the left and right, heat-sink mounted, Main Boards

I have three transistors, heat sink mounted, and they are:

#11- C1212-B
#12- A743-B
#6- C1628-0


In addition to those:

#1, #2, #3- A-872
#4, #5 - C-1918
#7- A-844
#8- C-458
#9- C-734
#10- A-561



Can someone please tell me what suitable replacements for these may be, or where to find the proper information?

While I have these out I will replace the electrolytics, 5 on each board, but should I replace any other components?


Thanks-

Jim

 

[avionic]

I would just replace the e-caps and refresh the heatsink compound and call it a day.

 

[brutal]

I am back to working on the CR-1020, after enjoying it for a few days.

On the left and right, heat-sink mounted, Main Boards

I have three transistors, heat sink mounted, and they are:

#11- C1212-B
#12- A743-B
#6- C1628-0


In addition to those:

#1, #2, #3- A-872
#4, #5 - C-1918
#7- A-844
#8- C-458
#9- C-734
#10- A-561



Can someone please tell me what suitable replacements for these may be, or where to find the proper information?

While I have these out I will replace the electrolytics, 5 on each board, but should I replace any other components?


Thanks-

Jim

If those are outhouse shaped SC458's, they need to be replaced before they go noisy (probably already are.) Don't pull the pads off like this joker did...

KSC1845 is a good sub and readily available, SC2240 if you have them. Pay particular attention to ECB orientation if they are replaced. Review this thread: http://www.audiokarma.org/forums/showthread.php?t=217432&highlight=2SC458

Like Dave said, leave the rest alone.

 

[vitalsigns65]

Ordered some KSC-1845

Thanks for the help!

From what I've gleaned the hideous SC-458 is a BCE, and the replacement KSC-1845 is ECB.

So then, the replacement will drop in fine once I've determined the correct orientation.

So I've ordered a count of 25 of these KSC-1845 from Mouser. I got extra since there are a handful SC-458 in a Pioneer SX-990 that I am restoring.

Which brings me to my next question:

Should I measure these KSC-1845 to find close values and If so how should I go about this?

My DMM has a dial with hfe- have no clue what that is, or how to use it, or if it's even necessary.


On a side note: Best to all my AK friends out there, and hope this finds you well.

 

[vitalsigns65]

Recap tone board?

Should I re-cap the tone board? It's a long board and looks like a pita to work on.

However, I see a lot of old caps on it.

Should I bother?

 

[avionic]

If those are outhouse shaped SC458's, they need to be replaced before they go noisy (probably already are.) Don't pull the pads off like this joker did...

KSC1845 is a good sub and readily available, SC2240 if you have them. Pay particular attention to ECB orientation if they are replaced. Review this thread: http://www.audiokarma.org/forums/showthread.php?t=217432&highlight=2SC458

Like Dave said, leave the rest alone.

One other minor issue with that transistor. It is held against the heatsink with a spring clip on its flat side. The KSC1845 and 2SC2240 will not be oriented correctly for the flatside.