• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Yamaha CR-640: Lights Up, Relay Click, Occasional sound drop unless I bump it

DallasSunset

New Member
Hi all,

I have been a lurker for some time and finally decided to seek help. I recently purchased a Yamaha CR-640 in near mint condition. Plugged into my Sansui SP-2000, beautiful sound and never had a problem. As a son of an audiophile, I always appreciated the warm Yamaha "smell" in our living room growing up, so I was happiest reliving my vibey childhood.

Unfortunately, about six months ago the unit randomly started losing sound. I would turn off, wait a minute, turn on, lights work and I hear a relay click, but 10-15 seconds in another click, and sound would stop. Then I randomly found out that bumping the unit on the top, in the lower left back (by power cord), would restore the sound.

Now the problem persists where sometimes multiple times per day, mid-listening session and receiver plenty warmed up, I get no sound. A quick "slap" on the top restores sound and might last 10 minutes or 3 hours or a full day, no correlation there.

While the receiver is still plenty working, I'd love not to have to slap it back to reality sometimes! Any idea on what is wrong?

I am somewhat experienced with electronics, welding, etc... but lack a voltmeter. Should I get one? No fuses are broken, no capacitor appears blown out, all pots / switches work with no scratching. I have an inkling the slap may reset a relay or some kind of fault switch back in place, but would like to see if anyone has experienced this problem before I buy voltmeter / deoxit and go to town.

Thanks in advance.
 
Register to hide this ad
It could be a cold solder joint and or dirty switches, I would say both.

Look for cold solder joints on the main PCB's and power supply boards. Also the switch boards solder joints.

it could be anywhere so basically check over everything. I know its not the answer to tell you exactly where it is, but when units are this old they need refurbishing with at least a reflow of solder joints and a good disassembly and cleaning of all switches and pots.

Athanasios
 
Back
Top Bottom