Sennheiser HDR 100, wires deteriated on transmitter. Can the transmitter be replaced?

no two different systems

The system is working in the 860 Mhz range, so not that common. Most of the time it is cheaper to by a complete new system then to tray to buy components. Just keep looking in the thrift stores you find a transmitter for this headphone for a good price.

what is the source of the audio? I would start by checking that first. switch sources to see if the transmitter is the problem if the transmitter is only getting the right side signal, that's all you'll hear...hope this helps!

wiring

If you twist the earpiece,one of them has two NIMH AAA batteries ,worth checking out if these are gone ,which is what happened to me.I was about to bin my rs130's and just stuck two new rechargeables and the earphones are working again!!!!!

As for $20 dollars from sennheiser for replacements!?!?!?
You should pick up two NIMH batteries for a couple of bucks on ebay or amazon.DO NOT USE ORDINARY BATTERIES!!!!!

http://www.jntworld.com/catalog/index.php?cPath=21_1002&currency=gbp&osCsid=c5b2f0de48c59564afb36dfebba513ac#tabbed_box_1

Here you will find something.

Turning the transmitter on and off (Fig. 5)
Turn on the sound source. This automatically activates the
transmitter and the green LED “ON/OFF” lights up. If the sound
source is turned off, the transmitter is automatically deactivated
after approx. 3 minutes (the LED “ON/OFF” goes off).
Note: The automatic level control only functions if the volume of the
sound source is sufficient.

A replacement battery can be purchased from Sennheiser for $20.00.
Battery Part Number: BA 151
Sennheiser Link:
http://www.sennheiserusa.com/newsite/productdetail.asp?transid=004146

A replacement battery can be purchased from Sennheiser for $20.00.

Battery is: BA 151

Sennheiser Link:
http://www.sennheiserusa.com/newsite/productdetail.asp?transid=004146

Yes, the switch is available from Sennheiser parts, and if you can get to it and know how to work with SMD's, it's quite easy.