Brown glue

[Jeff eelcr]

I was working on a BMW radio with a strange problem A pop in audio when Vol,presets,AM/FM/WB but not mode are pressed or turned.
I removed the glue from around the crystal which was dark and hard, also there was an insulator under the crystal.
TWO days later, several other problems found but still a pop in the audio I decided to look under the insulator there was more glue but
it was soft and flexable but I removed it anyway and the audio pop was gone.
This is the first time I have seen this glue cause a problem when soft and flexable.
Jeff

[jzx]

It seems that some glue, white-yellowish originally, when old and cooked becomes conductive, not much, but enough to create problems.

https://www.eevblog.com/forum/beginners/how-to-remove-the-dreaded-yellow-glue-of-death/msg4796963/#msg4796963

[madires]

That old circuit glue becomes conductive and corrosive with time and heat. It's a known problem. You did the right thing to remove it completely.