Yamaha CR 620 Phono Input Issues

[OisterMoist]

Hello everyone,

I'm currently working on a Yamaha CR-620 receiver I found at my local thrift store. I have cleaned it, changed the light bulbs, replaced the tuning dial cord, and cleaned the knobs with Deoxit.

It sounds great with my CD player, Cassette Deck, and 8-track player; the only problem is that the Phono Input doesn't work.

When I try to use my record player (Audio Technica LP60X), the speakers (mostly the right speaker) start making a cracking noise. I already tried using different RCA cables and a different turntable, but the problem persists. What is weird is that this problem only happens with the Phono Input; the rest of the Inputs sound perfect.

After some Google searches, I discovered the problem may be a capacitor or a fuse. I already tested the 3 fuses with a multimeter and all of them are good.

Does someone have any idea what the problem is? Or which capacitors should I change? I included some photos of how the unit looks.

 

[avionic]

Check solder connections on the PHONO RCA jacks.

 

[avionic]

Check that the +30 vdc power supply for the phono preamp is present at the pre-amp.

 

[avionic]

Check out C520 (47µf@35v) aluminum electrolytic. The positive pin of C520 would be a good place to check for +30vdc power supply voltage,

 

[Sparkplug]

If none of the above turns out faulty, I’d check C501, 502, 517, and 518 for solder joint integrity and general health. Good idea to reflow the equalizer circuit entirely anyway. Your problem might just go away. LOL.

 

[OisterMoist]

Everyone, thank you very much for the help provided.

I changed all capacitors and transistors in the Phono area, and now it is working perfectly.

For the record, the problem was one of the transistors (just in case someone has a similar issue and wants to figure out the specific failing component).