On Monday, January 20, 2014 8:39:09 AM UTC-5, William Sommerwerck wrote:
I'd been listening to a Sony SRF-80W (the original FM Walkman) while on the

treadmill. Several weeks ago it developed loud post-volume-control blasting

noises, so I went back to my iRiver.



Two electrolytics were the likely culprits. Yesterday I finally got around to

pulling out the 'scope, to confirm the diagnosis.



Yup. You guessed it.



The blasting was gone. So was the stereo. I adjusted the PLL lock pot (which

I'd done on several samples of this unit, including this one) -- and it

refused to lock. (This is not a critical adjustment. It can easily be done "by

ear".)



Isn't it fun to own classic, high-quality products that stop working -- and

there's no straightforward way to fix them?



Maybe when the weather warms up, it'll start working again. (Nah...)





"We already know the answers -- we just haven't asked the right questions.."

-- Edwin Land

About a year ago I was repairing my old Grundig "Transistor 305" AM/FM portable radio. I used to ride around The Bronx when I was a kid with this radio strapped to my bicycle. It's a nice old radio circa 1970. It had become intermittent and was driving me crazy. I posted it to this group along with the schematic posted somewhere else. (I don't remember how I did this but I had help), so that everyone interested could see it, and I got advice and help from all over the world. It was amazing. One guy from Sweden even sent me a set of germanium transistors and diodes for it. I also included with this good and bad voltages taken. It was months and my own radio so I kept at it and "we" eventually found the flaky coupling cap that was causing the problem. I hope that your experience is as positive as mine was. BTW if you think the Northwest is cold, try New Hampshire. Lenny