Sony Discman D-121 has distorted sound when AVLS enabled

Hi,

I'm having an issue with my Sony Discman D-121, the sound gets distorted when I put the AVLS switch on position '1' or '2' (the volume gets lower as it should, but also the sound gets very distorted). When the AVLS switch is set to 'OFF' the sound is great, the player works perfect. What could be the cause? Could be that the AVLS switch is defective? Should I try to replace the switch? The only thing I've tried until now is to use a contact cleaner on switch, but it didn't solve my problem.
Thanks.

 

Good thinking on the switch! That's a nice clean easy task to tackle. I don't think that's the root of the problem, but good to rule it out.

I'm not an expert with the D-121 specifically, but it is made in '93, and it does have SMD caps. 1993 was smack dab in the middle of Sony's capacitor crisis. I've said it before, and I'll repeat myself; ANY Sony product (Walkman, Discman, Watchman, Handycam, Video Walkman) from 1989-1994 that has SMD caps *will need recapping* before it will work properly. I had a handycam from 1993 with SMD caps... 143 of them. Every single cap had leaked. You could literally smell dead fish at the goodwill about a foot from the case I found it in!

Open her up and do a visual inspection. Look for caps with green/dull/corroded solder pads nearby. Also, grab a service manual for it and trace back the AVLS circuit to see what is in the circuit path for it.

 

I have a Sony D-FJ401, and one time last year I noticed that pressing the “bass boost/sound” button caused the sound to become distorted, but if I left it alone the sound was fine. It might have only distorted on the second press of the button, I can’t remember.

Months later, I pull the player out to use it and it played fine, no problem using the bass boost/sound button.

I think possibly it was the batteries were getting low when it distorted the sound, as I use rechargeables that don’t always have reliable “battery life” compared to alkalines. But it is just a guess, the only thing I did differently with player was put in freshly charged batteries.