Watch body cracking spontaneously

Hi all,

I recently noticed cracks that seem to be spontaneously appearing in the watch body of my Bangle.js, see photograph below. One large crack has appeared above one of the screws and I can see smaller, thin cracks appearing near the other three screws.

Now I don't remember dropping my watch and the way the cracks are oriented, it looks as if the back plate has been pulling on the four screws. Is it possible that the battery has swollen? I haven't opened up my watch yet, but otherwise it's working fine.

Wow, sorry about that - never seen that before.

If you could look inside the watch that'd be great - instructions here: https://www.espruino.com/Bangle.js+Disassembly

It could be a swollen battery. It'd be good to know either way - if the battery looks ok ideally I could just send you a new watch body and you could swap the innards over?

OK so I opened up the watch. I noticed that the back plate sprung back, mostly at the side of the crack:

Looking at the inside of the back plate, there seems to be a blob of some translucent material, with some excess around one of the pogo pins:

Could some of that translucent material have gotten caught between the back plate and the pogo pins' contacts, causing outward pressure on the back plate leading to the crack? On the one hand that seems consistent with the position and shape of the crack; on the other hand, it doesn't take excessive force to push the back plate into contact with the body.

Here's a picture of the rest of the internals with the battery, which doesn't look swollen to my (inexperienced) eyes:

I guess without a swollen battery we still have a bit of a mystery on our hands, but I'd definitely appreciate receiving a new watch body. I just hope that another part of the watch isn't the cause of this.

Thanks - yes, the internals look fine! I guess it's possible that the sealant on the rear plate caused the issue as you say... Please could you PM/email me your address and I'll get another watch body (and rear, just in case) out to you.

The sealant ring has to lay nicely in its groove. Furthermore, I hope the screws ware not too long and crating pressure from within the screw hole. It looks like layers separated... It could also be that on assembly the screws were not tightened balanced... like you do when you put a wheel / rim on a car.

I received the new watch body, swapped over the electronics and closed it up without issue. It's working perfectly again, thanks!