Last Tuesday, I was just leaving home on my bike, ready to go off for a spin and as I clicked down to go into a bigger cog nothing happened. The Di2 was giving its first problems in 33,000km. I have not had one single problem with Di2 since getting the bike up until now. It has worked flawlessly apart from when I forgot to charge it!
After 4 hours of working on the bike, I narrowed the problem down to the junction box because it seemed the ports were worn and the cables would not click in properly. I took it to the bike shop and sure enough they said it was a problem with the junction box and that it was just worn over time and because it hadn’t been updated in a while.
Now after installing a new junction box, I appear to be having problems with the rear derailleur. When I plug the cable into the rear derailleur, it works perfectly for a few hours and then just stops working. I get nothing out of it. When hold down on the rear derailleur shifter I still get light on the junction box. That narrows it down to the connection between the junction box and the rear derailleur. I have tried changing the cable and it doesn’t fix the problem.