BBSHD Speed Sensor Wire Torn Out

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Cyclist83   1 mW

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BBSHD Speed Sensor Wire Torn Out

Post by Cyclist83 » Oct 06 2018 8:09pm

I just finished installing a new BBSHD only to find the error code 21 after riding for a minute. Upon inspection I discovered that the speed sensor wire has torn from the controller side. Not sure how this happened, but what are my options for repair?
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Nicer   1 µW

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Re: BBSHD Speed Sensor Wire Torn Out

Post by Nicer » Oct 13 2018 7:33pm

Hi I have the same issue but with error 30 my back tyre was rubbing on the cable and cut into it.. have you had any luck fixing it.
Hope we don't have to buy a new controller.
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kcuf   1 mW

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Re: BBSHD Speed Sensor Wire Torn Out

Post by kcuf » Oct 15 2018 1:04am

tire rub repair splice isn’t bad if there’s some wire to work with.

yanked out of the controller is very hard to repair mostly due to potting used on controller pcb.

i dug out enough to reach solder pads but also broke off important inductor component and pretty much sealed the deal for new controller.
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fechter   100 GW

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Re: BBSHD Speed Sensor Wire Torn Out

Post by fechter » Oct 15 2018 9:41am

For sure the potting makes it a pain. Below is a picture of an unpotted one so you can see the target area you need to reach.

If you are lucky, there will be enough wire still attached to the board so you can splice. If not, it would probably be best to try removing the entire potted board from the housing. There are just two screws toward the ends of the arc-shaped heat spreader that hold the heat sink to the housing. Once those are removed, the only thing holding it is the potting. Go around the edges with a skinny straight blade screwdriver and try to separate the potting from the shell, then pry up on the main wire bundle.

You may also be able to reach the spot just by carefully digging through the potting with a screwdriver. Be careful not to use too much force or hit any wires buried in there.
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BBSHD speed sensor connections.jpg (49.77 KiB) Viewed 153 times
BBSHD unpotted board top small.jpg
BBSHD unpotted board top small.jpg (111.79 KiB) Viewed 153 times
"One test is worth a thousand opinions"

Nicer   1 µW

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Re: BBSHD Speed Sensor Wire Torn Out

Post by Nicer » Oct 24 2018 7:16am

Thanks for your help guys but splicing the wires didn't work for me I'm thinking the damaged bit of the wire caused a short as the error 30 still showed up.
I ended up buying a new controller for $180 (aus) not happy only had the motor for 2 months and it works fine now.
My question is, is there anyway to fix the damaged controller if it's been shorted or is blown. I'm willing to take all the grey potting out if it's possible to fix. I don't want to have to spend more for another controller if something happens again.
It would be awesome if I could somehow fix this controller rather then throwing it out.
Thanks

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fechter   100 GW

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Re: BBSHD Speed Sensor Wire Torn Out

Post by fechter » Oct 24 2018 8:08am

It might be shorted out further down. If you can dig down to the board so the individual wires are separated, you could use a voltmeter to measure the lines. The controller has to be powered up with display attached to test. Motor can be disconnected. With nothing connected, you should see something like 4.3v on both the 4.3 wire and the speed wire measured against ground. Also check continuity from the ground wire to the main battery negative. If the voltages are OK then it will probably work. Speed wire might be 5v.

If there is a damaged spot in the cable, the best thing is to cut that part out completely and shorten the cable.

If any of the wires made contact with the pack voltage wire in the cable, it's probably toast. If the input to the MCU got pack voltage, it will blow that input and destroy the MCU, which is not replaceable.
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TommyCat   10 W

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Re: BBSHD Speed Sensor Wire Torn Out

Post by TommyCat » Oct 24 2018 11:13am

fechter wrote:
Oct 24 2018 8:08am
The controller has to be powered up with display attached to test.

A programming cable can also be used... :wink:

Or a more direct approach, jumper the pins going to the display.


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