New rear Di2 not responding

First.Aspect
First.Aspect Posts: 17,379
in Workshop
I have 2015 ultegra Di2. That would be 6870 I suppose.

Have had to replace rear derailleur, because the hanger failed and it was pulled into the wheel.

The replacement won't respond. It is 8070 (begins with an 8 at least). Comparability charts say it should work.

Any ideas? The motor on the old one still responds, so the wiring is fine.

Comments

  • shirley_basso
    shirley_basso Posts: 6,195
    It definitely should work as I have installed an ultegra 8000 series rear mech on my otherwise 6870 di2 bike without issues.

    I guess the only obvious question is if your software is up to date?
  • First.Aspect
    First.Aspect Posts: 17,379
    Ah, no. Haven't touched it.
  • First.Aspect
    First.Aspect Posts: 17,379
    I also just bought a bar end junction box. Will try that. Guess it will have more up to date firmware.
  • BetterShifting_Terry
    BetterShifting_Terry Posts: 37
    Your new RD-R8050 is definitely compatible, yeah.

    You may have to update the firmware on the older FD and shifters before it'll shift, but it depends on when that was updated last.

    The easiest way to troubleshoot this is to connect it to a windows PC using the charger. It plugs into the bike and into a USB port on the other end. Then use E-Tube Project (3.4.5 is less buggy than 4.0.4).

    You can download that here: https://bike.shimano.com/en-EU/e-tube/project.html

    That should tell you (1) all detected components - double check the new RD is there and (2) whether or not any of the components can be updated.
    I run BetterShifting.com - Di2 help / tips / guides
  • shirley_basso
    shirley_basso Posts: 6,195
    Terry - can you help with another Di2 issue I have had?

    Thread here:

    https://forum.bikeradar.com/discussion/13114170/repair-dead-di2-rear-mech
  • First.Aspect
    First.Aspect Posts: 17,379
    Thanks guys. I'll give that a go.
  • pilot_pete
    pilot_pete Posts: 2,120
    Yes, usually it’s a case of the system just not seeing it. E-tube should sort that.
  • themxperience
    themxperience Posts: 29
    So, we're looking at:

    A) It worked, POST crash
    B) When plugged in it doesn't even show up/register.

    Something has come detached inside.

    Id be getting that sucker apart myself to see if I can spot it. I know an electronics engineer who can solder super delicate/fine stuff. These people are about if you look for them.
  • First.Aspect
    First.Aspect Posts: 17,379
    It was the firmware. Turns out the front mech is also knackered. Mechanically rather than electrically. Jesus what an expensive mech hanger.
  • shirley_basso
    shirley_basso Posts: 6,195
    themxperience said:

    So, we're looking at:

    A) It worked, POST crash
    B) When plugged in it doesn't even show up/register.

    Something has come detached inside.

    Id be getting that sucker apart myself to see if I can spot it. I know an electronics engineer who can solder super delicate/fine stuff. These people are about if you look for them.

    So your A/B is what happened to me.

    I'd be happy to send it off to your pal. I did do some Google searching but didn't find anyone. Can you PM me some details please?

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