[PLUG-TALK] Headset repair

[Keith Lofstrom]

On Wed, Jun 10, 2020 at 07:49:14AM -0700, Rich Shepard wrote:
> My Yamaha CM500 headset limits sound to the left ear. The company is
> replacing it under warranty and does not want the old one returned.
> 
> Has anyone futzed with fixing a headset? I've no idea how to disassemble it
> (so it can be properly reassembled) to trace wires looking for the problem
> and repairing it. It would be great to have a backup headset here if someone
> would be interested in the challenge of making it work.

I don't need another timesink, but I recently fixed one
of my old KOSS headsets, sorta ...

The headphone connection "cable" in my headset contained
four VERY thin braided wires (submillimeter).  Two bare
copper ground braids, and two braided wires with EXTREMELY
thin colored (red or blue) insulation, the signal wires. 
Very fragile without the strong plastic sheath, but very
flexible; presumably the design intent.

The break was at the entry to the plug, which makes sense,
as that gets the most flexing and pulling.  After cutting
the plug off the cable, and a couple of failed attempts,
I managed to separate the ground and signal wires and put
a bead of solder on each wire end.

I did not have a spare 1/8 inch stereo plug in my audio
scrap box, but I did have some "RCA" plugs.  So, I wired
each fragile branch onto the RCA plugs, then attached
those to an RCA-mono to 1/8 inch stereo adapter.

A horrendous kludge;  I'll be surprised if it lasts a month.
But I got to see what's inside the headphone cable. 
Flexible, lightweight, fragile, NOT durable, NOT repairable.
And expensive; my time costs far more than another headset.

My guess is that my headset (and yours) are manufactured
on completely automated manufacturing lines, not touched
by human hands until they are inspected and packaged. 
I cannot imagine how they could possibly automate the
diagnosis and repair of returned headsets.

I /can/ imagine them asking for returns on the first
thousand or so headsets that break, so that a quality
engineer can learn how they break, leading to design
and manufacturing and testing improvements.  

I can't imagine any practical way to make lightweight
headsets much more robust.  you can yank pretty hard on
a headset cable, hundreds of pounds of "snap" force.
If the cable was extremely strong (say braided Kevlar 
fibers inside), it would be (1) less flexible and (2)
maybe break the socket on your computer.  I prefer an
occasional broken headset, and a reminder to be gentle.

Keep your old headset ... you might break the headband
or other mechanical parts on your replacement someday.
Yamaha honored your warranty ... which is way cool, this
transaction probably ate up 5 times their profit margin.
Most warranties turn out to be "30 seconds or 30 yards"
from the retailer's front door.

Your warranty experience taught me to "buy Yamaha".
Thanks for that.

I bet you did not read the brief owner's manual. 
It could have been worse: https://xkcd.com/293/
 
Keith

-- 
Keith Lofstrom          keithl at keithl.com