REPAIRED:HP22S display working but with dark elliptical stain

[isanchez]

(I cut this repair explanation embedded in another post with different title, to allow a better access to the information about repairing procedure)

This method can be used in any Pioneer series display, with the same pathology.

Hi,

just to report that I have finally repaired a HP22s and a HP32s displays following your recommendations (thanks!!).
The process was absolutely satisfactory:

-Open the calculator following one of the many tutorials available.

-Remove the board, leaving the display accesible.

-No not remove the display in any way.

-Remove the two zebra connector stripes (the black band goes towards the display)

-Peel the silvered adhesive plastic sheet that is adhered to the display.

-Clean carefully the display glass with alcohol, removing the glue stains (if present).

- This is the most critical issue: what can be used to replace the mate silver coated sheet? I suggest the mate side of home-use aluminium foil...I have tested many sources without optimum display tone. Remember : the mate side, not the bright. Carefully cut the proper size..

-Place this sheet in the display and use your finger to place it avoiding wrinkles!!

- I find there is no need to glue the aluminium foil to the display...

-Place the zebras back in the right position (black band faced towards the display center)

-Install the board back (tightened firmly) and test the calculator before putting the back side back.
-You can glue the heads the four posts around the battery area. I do not recommend to glue the inner posts, as they can ruin the keyboard mechanism. I do not glue any part...it all keeps in place with solvency, just pressing it all back in place.

That's all!

I have pictures, but high res...if you want, I can post them...after resizing.

Hope it helps,


Kind regards

Ignacio