(define meta
  `((title . "A look inside the Kobo Touch")
    (date  . ,(string->date* "2013-07-25 00:00"))
    (tags "DIY" "electronics")))

(list
 (p [The e-ink screen of my Kobo Touch ebook reader broke, probably
     because it didn’t like being bent regularly.  It was a little over
     a year old when it happened, way too soon to give up on it, so I
     decided to take it apart and replace the screen if possible.])

 (wide-img "2013/kobo-broken.jpg"
           "the broken display")

 (p [If you want to open any device that is held together by plastic
     parts with teeny plastic flaps that snap into each other: use a
     guitar pick.  The Jazz III pick (my favourite) is very well suited
     for the job.  I used it to pry apart the plastic frame of my
     netbook before.  The Kobo touch is really a beautiful device (if
     you have one, I encourage you to look inside) and is much easier
     to take apart than my netbook.  The battery is much smaller than I
     expected and the PCB is very clean and ordered.])

 (figure "2013/kobo-inside.jpg"
         "After removing the back cover")

 (p [The screen is glued to a very robust frame (metallic, looks like
     iron) with two stripes of adhesives; with some nudging I could
     separate the two components.  The screen’s backside is shiny,
     polished; mesmerizing.  If you want to keep it that way, don’t
     touch it with your filthy fingers.])
 
 (p [Originally, I wanted to take the opportunity to upgrade the screen
     to whatever model is compatible with the driver chip.  This is
     printed on the chip:])
 
 (pre (code [E INK
TPS65185
TI  181
A49F G4]))

 (wide-img "2013/kobo-driver-chip.jpg"
           "close-up of the driver chip")

 (p [As it was difficult to get detailed documentation on the types of
     panels that can be used with the chip I decided to simply get the
     same model as the broken screen: ED060SCE LF T1.  The same screen
     seems to be used in the Nook.])
 
 (p [I paid CNY,(~)180 for a replacement.  It appears to be a more
     recent revision of the screen; there’s a little IC on the
     flexible connector and a few numbers on the labels have changed.
     It works fine, though ghosting seems to be significantly worse.
     The Kobo UI doesn’t always force a full page refresh; this only
     really affects the library browser, though. (The refresh rate can
     be configured for reading mode.)  The more often a part of the
     screen is updated the more gray noise appears all over the
     screen.]))