Reviving Sennheiser MKH capsule?

[Voyager10]

Hi all,

I've got a non-functional capsule from an old MKH 406 microphone:





(I swapped this for another capsule and the mic works fine).

There's a DC resistance of about 16K across the capsule. (My DMM's capacitance range reads ~25nF, but I wouldn't trust that a bit given the resistance).The diaphragm itself isn't obviously damaged.

Has anyone seen this sort of problem and fixed it? I've tried gentle cleaning with water and IPA with no change. Is a go in an ultrasonic cleaner a bad idea?

Cheers
Ian

 

[Tubetec]

It looks like the capsule has been clamped in a vice causing damage , maybe metal particles migrated and have caused a short inside , 16kohms where you might expect to see many many meg ohms .

 

[emrr]

One of the 416 T / 48v modifier guys mentions banging these on the tabletop has fixed many for him.

 

[gyraf]

..scary, but..

 

[soliloqueen]

If it is something loose causing a short You could try the whack. I would say avoid the top or the sides of the top obviously. A bit like settling the grounds when you're filling a coffee filter

 

[Voyager10]

I think I might try something more ... nuanced first. Maybe stick it to a speaker cone and vibrate it? If it makes any difference, I'll let you know.

 

[Icantthinkofaname]

If this is the same capsule as the 415, which I doubt, I may have a "spare". My 415T is really noisy, I don't know if it's the capsule or PCB, but it easily be the latter, it looks dirty and kind of has a smoky smell (like a chain smoker's house I guess?). I only know of one person who will service it, and I gotta dig through my email to find them.

[email protected] services some of the T power mics, but spare parts are unobtainium at this point.

 

[The Documentary Sound Guy]

I can confirm it's not the same capsule as the 415T. 415T uses capsule KS 15-4, whereas the 406T uses capsule KS 15-40. All details from the schematics in this post: Sennheiser