Sony ECM 377 mic repair- schematic needed please?

[barney]

Looking for a schematic if anyone has one. I have 4 here, one works, one dead capsule and the other two nosy preamps. I think it is the bias resistor causing noise but am unable to read the value, it is a green cap looking thing with a red mark?? The electronics are noisy without the capsule connected so am assuming it is the preamp or could it be the electret capsules slowly dying?

Any help appreciated.

 

[natek]

PM'd you with hopefully some help!

 

[mkiijam]

This is a big bump, but same issue on one and wondering what you found?

 

[gar381]

I have owned one for 40 + years with no problems but would love to have a skitz if
anyone can share. Real nice mic BTW

Gary

 

[Khron]

Internal photos could possibly help. Is the circuitry that complicated?

 

[rackmonkey]

Here you go