M92 display problem (faint random pixels); Anyone recognise symptoms?

[pieterc]

Hi everyone,

I can see that my M92 boots up, but it displays faint random grey pixels that slowly gets darker over time. When I navigate the main screen using the joystick, a faint big rectangle moves around which I recognize would have been updates of the big application icons.

This leads me to conclude that the CPU is fine and executing, but the e-ink display is not working correctly. It is as if the contrast is way, way down and it makes it impossible to see what is supposed to be displayed. I have attached two pictures to show what I mean.

To my best knowledge, the unit was never dropped or handled in a rough manner. It just started behaving that way when I powered it up one day after a few years of good service.

Does anyone recognize these symptoms? Any repair hints? I'm an electronic engineer and prepared to fix it myself, but a cursory examination inside did not reveal any obvious problem (like a bad solder joint or torn flexible tail).

Would a factory reset to defaults help? How can I accomplish this without seeing what is supposed to be displayed?

Thanks in advance,
Pieter

[pieterc]

Good news! (for me at least).

See attached pics. The e-ink display has a flexible tail that is folded with a Z bend. The right side was pressed down so hard that the tail tore and 4 tracks "just" made contact initially, but became intermittent over time. I scraped away the insulation, tinned the tracks and soldered a thin sliver of copper wire on to each track. Impossible without the right equipment, a steady hand and extreme patience!

Regards,
Pieter

[Randy11]

Beautiful job !

The screen show some black lines when it is broken, not something like yours.