Yamaha CR-220 Sound issues

Keneye

AK Subscriber
Subscriber
Hi, have a Yamaha CR-220. When you turn it on, plays fine. But, within a few seconds fades out to static. Turn it off, then turn it back on-same thing. I am thinking power caps? Already reflowed a few iffy transistor solder joints. Bought all 4 transistors to install IF that may be the issue. Can anyone point a newbie to some areas to explore?

Found the screws on the transistor bar were loose. Tightened them and now get continuous sound but distorted and staticy. A while back a friend who is a tach put two pieces of thin cardboard under the transistor bar. That worked for a while. I resoldered all the transistors.
Also cleaned all the pots and switches with DeOxit.

Sound only on mono not stereo. Meter working. Transistors 2 and 4 have no reading on the multimeter.

Thanks for any help.
 
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First and third are missing fasteners. What part numbers are printed on those two outputs?
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I took off screws after testing. They read A771 7NY. I have new replacements. Just wanted to be sure they are the issue.
 
Have you removed them from circuit and tested them. One of the 2SA771's is for the left channel and one is for the right channel.
A while back a friend who is a tach put two pieces of thin cardboard under the transistor bar.
Photo what your refering to.....:thumbsup:
These transistors may not be bad
Transistors 2 and 4 have no reading on the multimeter.
my problem is the first and third transistors are not reading on meter.
To me your describing a power supply issue.
Have you tested all the fuses with a multimeter Ω check?
 
Ok. I confess my sins. Yes, I am an idiot. I visually checked the fuses and reseated them. But the 1/2amp fuse was blown under the cap. Put in a new one and it's alive. Man, do I feel like a nube. Anyway, thank you all for your help. I need to smoke a cigar and reflect on being a dumbarse.
 
Well. Replacing a fuse is a heck of a lot easier. Then the alternative.:thumbsup:
 
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Odd thing is I have stereo light but no dial light or meter light. But playing fine and meter responsive.
 
Contact Dave at dgwojo.com He is the light bulb guy. Yamaha Cr-220 -- 2 ea. 14.5v@80ma bulbs.
 
Removed cardboard before I began trouble shooting. Just one 1/2 amp fuse blown under the cap. Visible part of fuse looked fine. Since it was half way working, I incorrectly assumed it would not be a fuse. Lesson learned.
Is the power light also a 14.5v 80 ma?
 
All lamps are the same.Schematic only shows two lamps and two red LED's.
 
I noticed 14.5 bulbs are a bit pricey. But you can buy bundles of 12v wheat bulbs cheap. Could I put a resistor inline to drop the 14.5 to 12? It would be nice to buy bulbs in bulk and they use resistors to adjust voltage for the various brands of receivers.
 
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