Polaris OBark

I know where we could get them replacement logic boards, really cheap.

Polaris OBark

Some people like to gloat when someone who lives a healthy lifestyle nonetheless contracts a terminal illness.

smd4

If you need a degree in electrical engineering to fix your bike, maybe you should take it into a bike shop and spend the bucks to have it done correctly.

This isn’t rocket science. But we’re getting there.

Polaris OBark

Last time I wandered into my garage, a whole 3 out of 12 bikes had electronic shifting. Of those, the government only forced two of those on us at gunpoint.

MichaelBicycles

To be fair though, even the bike shop employee is going to be a loss more than 9 times out of 10. They can maybe replace, but actually fix a bit of a stretch.

Polaris OBark

One can order a battery from Univ Cycles for about $120 (11-speed). (List price is about $160). You plug the battery into the cables, run Shimano's zero-cost software, and you are done. I built my wife's Di2 bike up (you can find my threads on it here somewhere). It isn't very hard, even for someone like me, who isn't particularly skilled as a mechanic.

(I'm confident the OP wishes he hadn't attempted a short-cut, but I don't feel a need to rub it in.)

Steve B.

Well, yes that’s how it should work. Re-reading the OP I discover that the system was modified as an attempt to not buy a Shimano battery, with a result that something in the system is dead. So this advise is completely useless.

Polaris OBark

It wasn't offered as advice. The OP already knows this (maybe read the original post a third time.)

It was a refutation of the baseless claim that one required a degree in electrical engineering or rocket science in order to service a Di2 installation.

simmsa

If I had known there was a risk of short-circuiting I would have never soldered any batteries, my ignorance about the fragility of these types of electronics caused this mess, completely my error and hopefully others can learn from my stupidity. Basically what the bike shop told me after replacing the fried front junction box is when individually connecting all the components to test them they all work properly during diagnostics. When hooking them up to the battery, the components don't connect and there is no shifting. It seems like there should be some way to fix this with a di2 expert I will try messaging bettershifting. Otherwise I learned a very expensive $2k lesson and will have to buy a new Ultegra Di2 8150 group or try and hunt down an out of production mechanical 8000 but I have found it very difficult to find a long cage derailleur and a 50/34 165mm crank which I want to switch to save my knees. I am finding it difficult to find any good condition out of production Shimano mechanical rim break groups.

Polaris OBark

I am only guessing, but I think you might have something as simple as a damaged connecting wire or a loose connection. If the individual components pass the diagnostic, they are probably OK.

I've switched over to 165mm cranks and 46/30T (GRX) cranksets.

Hopefully at least the shifters are OK, as those are the most expensive (and with rim brakes, hard to replace at any price). Does your new battery pass the diagnostic testing? Is the firmware updated in the battery, and everything else, so that it matches? I have a pair of 2014 Ultegra 11-speed Di2 derailleurs sitting in a box (rear one works with a 11-36T cassette) if you want to try those. But I am guessing you are one step away from getting it to work.

simmsa

Connections have been checked, any idea how the wires would be destroyed during the short? I would assume the other junction boxes could also be damaged, so I would have to replace all wiring and boxes to re-test? The battery was brand new and passed, the firmware was updated on all components. At this point I have my bike back from the bike shop after they advised me they tried everything Shimano advised and could not fix it.

Chuck M 

simmsa, can you upload some pictures of this soldering job? The forum will tell you that you can't because you don't have 10 posts, but they will still upload and someone will do a pic assist. I think your friend probably got the polarity wrong or something. Often electronics of this nature can protect themselves from this kind of thing.

Iride01 

It seems that the OP said the shop told him another component is damaged and not working. So if that was from incorrect voltage, whether too high or reversed polarity, that item will likely need to be replaced regardless of battery used..

Polaris OBark

Yeah, if they diagnosed the parts in situ, and everything passed, I think it is unlikely the wires are damaged.

If they checked each component individually, that is different.

As far as I know, the wires are just very small diameter coax cables, so I was speculating one could have been damaged by a short or surge (as if it were a fuse).

Polaris OBark

They told him the junction box needed to be replaced, so he/they did.

Maybe read a fourth time, this time for comprehension.

simmsa

I uploaded the photo, that's what I thought as well as the battery PCB has a ground wire, you can see on this image that the side of the battery was originally soldered instead of the metal tab. I'm pretty sure the polarity was correct as we copied the original battery polarity.

Polaris OBark

Is it this?

simmsa

Yes

maddog34

try and recall that it died BEFORE the re-battery attempt was made... and that repair attempt might have fried more things, but it will take another stack of cash to determine how bad the damage really is now...

and i still think the whole trend towards button pushing is a farce... kids walk by poking their phones and listening to concert level violent poetry, unaware of the car approaching from behind, or the charging pitbull about to snack on their thigh muscle... or the absolutely stunning fall weather complete with colorful foliage displays...
i'll keep using my time tested bar end shifters and inexpensive twenty year old derailleurs that don't need new batteries.

Koyote

Nothing died; rather, his Di2 battery was wearing out. And if he'd simply replaced it with a new Di2 battery, everything would've been fine.

maddog34

depending on the gauge size and material involved, a sharp bend or pinch can damage the central conductor.

Koyote

I see that you edited your post to acknowledge the reality of the OP's problem, since you had missed that...And instead turned it into an anti-technology rant. That's progress, I suppose.

maddog34

you see what you want to see.

Chuck M 

Assuming the green batteries are the new ones, it doesn't look like they are both hooked up. Do you have a picture of how your friend did this?

Keep in mind, I've never worked on an electronic shift bike, but I'm guessing that the batteries should be in series. BTW, the white batteries look like your friend did a number on them, it is possible that he simply damaged a connector or wire as Polaris OBark mentioned. If so, I can see why a bike shop may not have wanted to get too involved with this.

simmsa

From what I understand from bettershifting, the only way to troubleshoot this issue would be to test connect the battery and junction box with 1 wire or a new wire which should work since the components are new, and the individually add all the components other components like junctions, shifters, derailleurs until it breaks so I may go to another LBS to see if they have any spare wires and are able to test the components one by one.