Shure KSM44 repair

I'm new to this site, and have searced several threads for for this information, but nothing's come up.
I purchased a Shure KSM44 on-line, which showed up dead. Some poor packaging may have been the culprit, or maybe the mic was a dud. The seller refunded my money, and after hassles with the shipping company, told me to keep it. It only produces pos when the setting switches are toggled. Some of these pops are louder than others.
Well, i replaced the mic, and am pleased with the KSM44 I got. So, I figured I'd open up the dud, and see if I could find something obvious. I didn't. I did not. I was able to get tapping sounds when I tapped the RPM 130 cartridge, and when I cupped the capsule and growled, but the signals are low; much lower than the popping between the omni and cardiod settings. Can anyone help me with troubleshooting this mic if it is the pre-amp or the capsule?

Hard to say....probably the preamp, if you can hear it but very quiet. But the audible "pops" might make one think its the capsule.

Probably a loose connection somewhere.

If you can't get it to work you could always sell it to.....Me!

haha!

goodluck

Yep,
Hard to tell... I hoped tapping around the boards and switches while the mic was live would produce a result, but i got nothing but the low volume tick. I will look into the connections between the boards for a loose one. That's a good idea. Thanks.
I may sell it to you...but I'll have my way with it first. (Sinister) Hahaha

Its all SMD isn't it? You could try to replace the capsule, if not temporarily to see if that fixes it. You know, it might be better  to replace the other circuitry, you could build a simple fet circuit on a perfboard, probably sound better than whatever shure has in there anyway.

Yeah, Abe is right.  You could probably pretty easily make it better.  Those mics never impressed me.  They sound dull and lack detail.  Some call it warm but its really just dull.  I had one and sold it.  I would be very curious if you find a good little fix for it.  Other wise I bet you can contact Shure and they could probably fix it.  Maybe even not charge much at all for it.

As you would expect, Shure wants more than its worth to fix it. That was step one. Step two was figuring how to get it apart. I got past that. I am amateur enough to admit the working KSM 44 I have is better than my Oktava 319 and modded 012s for my vocals. Maybe I'm lingering from 30 years of rock bass ear destruction. I let my budget be my guide. I am more interested in troubleshooting this one without dropping three bones on a replacement cartridge. Can it be done? And how? So far the loose connection test is one I can pursue. I have a multi meter and a power supply, and it's already broken...

Ok, well I would start off looking for anything obvious....like loose solder joints wires, visual inspections can catch a lot of faults. Also good job on getting those things apart. I had a more inexpensive version of those mics, and wasn't very impressed and sold it, but het the look nice, and I heard the 44's are much better.

Anyway, look at the capsule, unless it is visibly damaged I would guess it is OK, for now. But be sure to protect it while you work on it, put a little zip lock bag over it or something.

Thanks,
Upon close examination of the capsule, the membranes appear intact, but there is an inconsistant offset between the edge of the ring casing and the membrane. This is on the side where the retainer insert appears pressed into outer casing. It is a slight offset, but noticable. Never having seen a pristeen capsule, I find it suspect. A full board and contact examination under a magnifying glass (man there is a bunch of stuff crammed on these boards!) nothing looks lifted or dull. The xlr connections are obscured by the structure, but appear to be connected well. There is noise produced by touching the capsule leads, and a faint radio station can be heard if contact is prolonged. (Not one I listen to) Other than acting as a human antenna, I think I've exhausted the bang it till it makes noise approach. It's reassembled, wrapped in bubble wrap, and put in the dessicant rich graveyard of busted stuff. I'm reluctant to dissassemble my working 44 and bridge the capsule leads as a test for fear of busting the perfectly good one. I may try that when I have finished the projects for which they were purchased. Any cautions about that approach? Seem's like a logical progression, but at the risk of sending two mics to Shure for repair, I may want to drink about it for a while.

interesting. yea i wouldn't want to open a working mic to try and fix a broken one either. but you could (at some point) get a cheap capsule and test it.

Have a good one!

Now there's a thought! I have a Behringer B1 that's being used as a space holder in a mic case. I wonder if it's body is a suitable donor body for a DIY Neumann 87. If I don't find it in a search, I think I'll head over to that thread and ask.
Thanks!

If youre interested in dumping the corpse, let me know, i may be interested in buying it from ya.

Happy ending. I shipped it off to Shure and they replaced it for free. I just included my invoice for purchase and a description of my problem, and waited.
Thank you Shure! I'll be recording in stereo now.