ppppenguin wrote:The connections to the sounder are soldered at both the sounder and PCB so tarnished contacts seem unlikely as an explanation. Only the sounder didn't work. Rest of phone was OK.
Fortuantely the cases went back together without apparent damage.
Inside the sounder there may be dry joints or just bits of metal kept in contact by natural elasticity and reliance on them not being tarnished, or not tarnishing within the expected life of the product. You're not going to take a sounder to bits and reassemble it. Surely not.
I have an expensive Yupiteru scanner which started playing up and which had nothing obviously wrong when it was opened up. I tried an osteopathic approach in desperation, twisting one end one way and the other the other way. It's been OK for the past ten years.
Duff connections, flat batteries and bulging electrolytics cause about 95% of problems in modern equipment in my opinion. Duff connections, especially dry joints have always been a major source of problems.