Owon PDS 5022S

A few years ago, my Owon PDS 5022S oscilloscope failed with a strange
looking display.  See photo at:
<https://photos.app.goo.gl/rYGeaGygSMXHtMCb8>
From what is visible on the display, everything seems to be working
except for the strange display.  Whatever is wrong is probably in
either the color LCD display or the circuitry that drives the display.
Does anyone have a clue what might have failed?  Mostly, I'm trying to
save time fixing it.  (I haven't torn it apart yet).

User manual (no schematic or block diagram):
<https://www.saelig.com/downloads/pds5022s.pdf>
Specs:
<https://www.batronix.com/shop/oscilloscopes/digital-oscilloscope-pds5022s.html>

--
Jeff Liebermann                 jeffl@cruzio.com
PO Box 272      http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann      AE6KS    831-336-2558