transponderserivices.com .... their in austrailia but they are quick, fast , and reasonable just had mine done same issues heres the email he sent me how to ship and price...

In most cases these transponders just need a new battery fitted.
AMB/Mylaps do not service or sell parts for their transponders so no point in contacting them unless your transponder is still under warranty.
Battery replacement costs $75AUD for old style and $69AUD for new style. USD and AUD are about the same value.

Many USA clients use USPS International Air Mail 5" x 8.25" Cushioned Mailer $1.19USD plus $12.75USD postage to send a single TranX type transponder. See www.usps.com

If you decide to send your transponder please enclose a completed repair form which you can download from my web site.

Best regards

Jeff Chandler
Transponder Services
tel: +61 7 3355 7476
mob: 0418 783 201
mailto:enquiry@transponderservices.com
www.transponderservices.com