Di2 Issue - WTF!

DirkVoodoo

I'll need to add some photos later, but something has happened my Di2 and I can't find anything online that sounds similar to it. Maybe someone here has experienced the same.

System: Ultegra Di2 6870 (Bought in Oct 2014). It's been nearly bullet proof during that time. No crashes or big hits, just the usual wear and tear. It's been out in nearly all conditions.

Issue:

• Over the last 12 months, the rear mech would perform intermittently. It would just stop working. No lights from the shifter. Then it would start up again. At first I thought it was a loose connection, but checking everything had *clicked* in correctly didn't change things.
• About a month ago, the unit just stopped working altogether. Even the front mech stopped working. Ok, needs to be charged?
• Plug it in to the BCR2 and no lights come on. Just a buzzing noise from the BCR2. Must be the battery, I guess 5.5 years is good going. I order the new DN110.
• When it arrives, I hook it up and still the entire system is dead. WTF!
• Furious, I just take the whole system off the bike and start playing around with it
• Plugging in only the battery > Junction A > charger = it charges
• I add in junction B > still charges... great!
• I add the front mech and the front shifter > still charges and the mech shifts just fine. Even using the old battery, everything works
• This is where it gets weird. If I add one or both of the rear shifter or rear mech, the unit goes dead and no longer takes a charge. Front shifting no longer works.
• Removing both rear shifter/mech > everything is back to normal > charges and front shifts

I plugged the whole thing into my laptop:

A) BCR2 + JCTA + JCTB + front shifter + front mech = recognizes all units
A + adding the rear shifter = recognizes A but "unknown unit" for the rear shifter
C) Adding rear mech to B = nothing is recongised and I get a prompt to plug in the BCR2 unit

It looks like I need to replace rear mech/shifter...great. But I just want to know "why???"...what is going on with them?

ednwireland

you just put me off buying di2

easygoing39

Bring it to Cliff in Harry's Bike's.

clog

Prob only needs software updates. Proper pc linkage will check and ensure all of the system is on same version. (esp if not touched since 2014) and introducing new battery. It can also diagnose other problems at the same time. Any shop with the Shimano pce-1 interface should be able to do it.

I have a unit but prob too far away from you.

Miklos

Yet another sign of the impending robot apocalypse.

07Lapierre

Have you tried switching it off and then back on again?

Sorry that’s as far as my IT assistance goes.

iwillhtfu

Sounds like something is grounding out in the rear mech/shifter killing the power and considering it's happening with either it could be the cable/signal wire. Can you borrow another cable or are they interchangeable could you use the front one for the rear and try your test again and see if the front trips it.

The charger won't work if there's a dead short to ground.

Diarmuid

DirkVoodoo wrote: »

[*] I add the front mech and the front shifter > still charges and the mech shifts just fine. Even using the old battery, everything works
[*] This is where it gets weird. If I add one or both of the rear shifter or rear mech, the unit goes dead and no longer takes a charge. Front shifting no longer works.

There's a short in there somewhere. It's strange that you say either or of the two additional parts cause this issue but considering the history, I'd start with the rear mech. I wouldn't fancy your chance of finding it unless you like tinkering with a multimeter, and that's assuming the electronics are accessible

godtabh

I had something similar and it was the battery losing its charge. Eventually just went.

DirkVoodoo

iwillhtfu wrote: »

Sounds like something is grounding out in the rear mech/shifter killing the power and considering it's happening with either it could be the cable/signal wire. Can you borrow another cable or are they interchangeable could you use the front one for the rear and try your test again and see if the front trips it.

The charger won't work if there's a dead short to ground.

Yep, cables are interchangeable, I've swapped them all around.

It's definitely not the battery as I've tested with a brand new one and issue remains.