Always a good day when you can learn something.

Good Video - Thanks for sharing !!

Sounds like a flaw in manufacturing of the filters. They could have been contaminated before sealing or the seals failed in service. Might be a good idea to keep a few on hand in a vacuumed sealed container. A good question to ask the customer is if the radio is used or stored in a damp and or humid environment. After working for 30+ years as a comms tech I made sure I invested in some good desoldering systems from PACE. One need the right tool for the right job. I refused to work on hilljack hacks upon opening the radio to find the customer has already tried his own repairs. My rates were posted. Factory clean radios cost $75/hour but hacked radios went for $125/ hour. No if's, and's or but's. And that was if the radio was not seriously burned or missing traces, plus NO WARRANTY ON REPAIR WORK ON A HACKED RADIO.

Do you have trouble sourcing ceramic filters? Are they OEM form yeasu ?

Can I send you my 857 to replace the filters? I have the filters, I’m not as good as I used to be with the soldering iron.