Boox Tab Mini C severe ghosting ==> Faulty TCON-B controller?

[Anghirrim]

New pictures for those who are interested.

Seems like the screen can only be changed by removing the front glass.... No luck the back.

Let's try....

[Anghirrim]

Well, once the adhesive at the bottom of the screen is softened with heat, gently cut through is, little by little.

You may have more chance inserting a thin foil on the edges first. The adhesive here is weaker.

[Anghirrim]

And finally, the glass layer is stuck to the eink screen with a strong adhesive mass (probably LOCA).

It seems to react well to makeup cleaning solution, so for sure it should be fine with alcohol.

Now time to see if I can find a replacement eink panel and associated adhesive, seems like OCA film or LOCA is the way to go....

[Renate]

I don't recognize your OCA or LOCA.
The black gunk is standard Tesa double stick.

[Anghirrim]

Originally Posted by Renate

I don't recognize your OCA or LOCA.
The black gunk is standard Tesa double stick.

Hmmm, isn't this jelly glue the LOCA? This is what was sticking the external glass to the eink panel (to the touchscreen layer actually).

There was of course the black adhesive all around, plus the jelly transparent adhesive between the screen and the glass.

[Anghirrim]

And the eink panel (eink screen + light + touch) back to the case. The entire surface of the screen was stuck with the jelly glue to the external glass layer (previous picture).

[Anghirrim]

Well, the gummy transparent jelly is apparently LOCA glue. At least I have experienced something very similar to this video when separating my front glass from the e-ink panel.

The second hand Tab Mini C with a broken front glass (but working e-ink panel) is on its way. I should soon be able to see if everything goes fine. Let's hope I won't break it.

[Anghirrim]

After a few hours of work.... it smells good. I bought a broken Tab Mini C on eBay (the front glass was broken, but not the e-ink screen).

On the left, my original front glass. On the right, my tab Mini C frame with the replacement screen.



I managed to remove the shards and clean the screen. Need some polishing of the touch panel as removing shards made a lot of tiny scratches on the panel.

But... everything is functional. LOCA glue + UV lamp ordered, it'll arrive on Thursday. Seems like after all I may save my Tab Mini C.

If successful, I'll create a step by step disassembling and screen replacement guide (which I DO NOT recommend to anyone. You'll have to be crazy or desperate to attempt it. The risks are way too high to end up with two broken devices).

[Anghirrim]

Side question, the Tab Mini C I bought on eBay is from 2024, while mine is from 2023. Is there any preferred mobo to keep?

The two mobo's are not of the same revision. And some chips are different too.

They both have the exact same booting time, so no comment from a performance perspective.

I'm more guessing if they made some upgrade related to what could have caused the ghosting issue.

Attached, some pictures of the 2024 mobo (on the pictures with the two mobo's, the upper one is the 2023). We can see that they also bridged/shortcircuit two points close to the e-ink screen connector.