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Discussion Starter · #1 ·
I left the house this morning and checked the battery level by holding down a button on the shifter (6770) the front LED flashed green, so I figure im good. As I start riding, neither the FD or RD is working. completely dead.

Ive checked all external wire connections on the FD/RD/Shifters/Front junction. Ive confirmed that both left and right shifters operate the front junction LED. Ive gone into crash recovery mode via holding the front junction button for five seconds and getting the flashing red LED.
I have also removed the battery to try to force an electrical reset.

I have not checked the rear junction as its inside the BB.

It could be that both derailleur cables came loose from that - unlikely
It could be that both derailleurs are dead - also unlikely

Ive searched google and not found anything. Anyone have any other tips?
 

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Most of the connectors have "2 clicks to make", you probably only pushed them in to the first click.
 

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Check plugs at shifters.. Meaning unplug completely and replug


Sent from my iPhone using Tapatalk
 

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Discussion Starter · #6 ·
Hmm, I havent tried this yet. I dont have a charger handy, but every time I do the battery check, it still flashes green.
 

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Discussion Starter · #7 ·
Just tried this, FD/RD still dead, but the front junction LED still flashes green when testing with any of the four shifter buttons.
 

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It's odd that both derailleurs failed at the same time.

The internal junction box has 4 ports: Battery, Front junction, Front derailleur, Rear Derailleur.

We know the wire from the front shifters stem junction is working, since the junction box has the LED light working.

The battery wire must be connected, too. I doubt that both front and rear wires disconnected at the same time.

The internal junction box, from the Di2 Dealer Manual PDF:
View attachment 315185

It appears that both the internal and front junction boxes work like a network switch, so that cables can be plugged into any port. You could try swapping cable connections on the internal box--exchange the two cables on the same end of the box. Then see if anything changes. A new junction box is about $20.


E-tube software

Do you have the e-tube Di2 software? user guide pdf. It has an error check button, which may help.
 

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Sounds like you have a bad cable or junction box going to the derailleurs, but not knowing your setup, it's hard to say.

The ETube software will tell you what is connected, and do some diagnostics. It will also allow you to update firmware (for anything it can connect to).

Also, if you have a D-Fly, you can pair to your garmin/wahoo, etc... and see the Di2 battery status.
 
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