Bangle.js 2 Screen Flickering

[espruino-discuss2]

Posted at 2023-10-07 by user156702

Recently my Bangle.js has started having issues with its screen. The display flickers very rapidly, and when the backlight is on it still flickers and looks very washed out. I have tried doing a factory reset and updating the firmware to 2v19, but neither solved the problem. There are some times where the screen functions as normal, such as the DFU screen and the intro sequence after the factory reset. After that, it's back to the flickering. Has anyone else encountered this?

[espruino-discuss2]

Posted at 2023-10-09 by @gfwilliams

Hi - sorry to hear this. So the backlight doesn't flicker, it's just the screen itself flickering?

Do you think you'd be able to post a video?

It's strange about the flicker - does it still not flicker in the intro sequence now you're running 2v19? It could be some kind of issue with something called the EXTCOMIN line. It has to be triggered every so often to avoid ghosting (less when the watch is idle, we don't bother at all in the bootloader, and older firmwares had a glitch where the welcome screen didn't do it either).

Just to check, but did this flickering coincide with the Bangle being submerged in water for a while, like swimming, baths or similar? It could be related to water inside it.

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Posted at 2023-10-10 by user156702

It looks like it's just the screen flickering. As far as I can tell it doesn't happen during the intro sequence still, but it's hard to see while the backlight is on (as of 2v19). The colours on the screen also invert when the backlight is turned on, which hasn't been always happening (before it seemed to just get a bit washed out). I've been keeping the watch away from water, so I don't think any could have gotten inside it.

In the video, the flickering while the backlight is on is easiest to see right before it switches back off.

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Attachments:

• vid.mp4

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Posted at 2023-10-10 by @yerpj

13:37 coincidentally ;-)

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Posted at 2023-10-11 by @gfwilliams

Thanks for the video - that's really interesting. Having the display invert when the backlight turns on is very strange - it's another sign that something is broken on the connection to the LCD.

Either there's something like corrosion on the PCB shorting the pins together, or perhaps the connection to the LCD itself has come loose.

I'll send you an email in a second - looks like you didn't get the watch that long ago so I'll see about getting you a replacement.

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Posted at 2024-03-19 by user157779

Hello! Please tell me where I can buy a display for Bangle.js 2?
Same thing happened to the screen on my Bangle.js 2, factory reset didn't fix the problem either. Sometimes the flickering and inversion stopped and the screen worked as it should. Searches for information on this issue turned up nothing, so I resigned myself to it and put Bangle.js 2 in the box with a shutdown.
Earlier this year, I came across @espruino's "Bangle.js 2 Disassembly" video and decided to try opening the watch and poking around in hopes of finding the cause.
But the display was held very firmly and by heating the display to 70C°, then to 80C°, I could not disassemble the watch. After raising the heating temperature to 90°C, after several attempts, it was still possible to peel off the display and disassemble Bangle.js 2.
But due to the heating, the display became stained and darkened.
I didn't find any flaws or damage in the middle of Bangle.js 2, so I hope that replacing the display will bring my Bangle.js 2 back to full life.

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Posted at 2024-03-19 by @thyttan

Available on the espruino shop: https://shop.espruino.com/banglejs2-lcd

:)

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Posted at 2024-03-20 by @gfwilliams

Argh, sorry to hear that - it can be a real pain to get the LCDs off without damage - but as @thyttan says we do stock new displays and they're not too expensive.

It's quite likely that the issues you were having were just due to corrosion on the LCD connector - so I imagine it'll work fine with a new LCD.

While you have the screen off I'd give it a quick clean with isopropyl alcohol and a clean brush just in case there was some kind of corrosion causing an issue though

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Posted at 2024-03-20 by user157779

Thanks for the quick reply, link and advice.
I carefully examined everything inside, I did not find any signs of moisture or corrosion on any element. But probably everything should be carefully examined again.