My Di2 is Broken!
In order to gain access to the Shimano synchro-shift feature, I decided to upgrade my Ultegra Di2 drivetrain by adding a new battery (BT-BN 110) and the wireless unit (EW-WU 111). I followed the instructions I found on YouTube videos, but have yet to achieve success. Specifically, the rear derailleur no longer responds, nor do I get any response from the LEDs on the junction box when I depress the button underneath. The only way I get an LED response from the junction box is when I hold down one of the shift paddles/buttons.
It's probably worth mentioning that the components comprising my drivetrain are a mixture of 6870 and 8050. Both derailleurs are of the 8050 variety, but I believe the shifters are 6870.
Charging of the new battery appears to have completed successfully. To eliminate the possibility that the rear derailleur was not getting a signal, I double checked all connections.
The author of a YouTube video about installing these components reported similar symptoms. He had to remove the wireless unit to get everything working again. I have yet to do so. Doing so would be a last resort. Once I remove the wireless unit from its current location, it will be difficult if not impossible to reach the end of the cable. But at this point, I have run out of ideas. I guess I'll try removing the wireless unit now. In the meantime, any other ideas are welcome.
Last edited by babyboomer; 05-24-21 at 11:04 AM.