My g-5600e already 12 years. No point salvaging it... Might as well let it retire. You also say can't wipe away the fog...
Bought gw-b5600mg cos it's cheap! $118 only with the fancy features and white backlight! Iirc I got my g-5600e ard $100+ too back then.
Din know about g-5600u, will Google for it. Led? Or lcd??
Edit: Got gw-b5600mg cos of the positive display, monotone green wordings work for me too. Hated negative display.
they updated the bunch of older non-bluetooth squares like G-5600e, GWM-5600 and GW-S5600 from EL to LED... so all carry the U prefix.
iirc the time displayed in STW and TMR in the bluetooth models are now also present in the U modules.
U modules dont have bluetooth, but they have they retained their battery indicators that were absent on B5600
i also bth negative display. got the B5600AR for the looks back then, but viewing angles were just bad... so i inverted it after seeing the results from this reddit guy's work
the red from a transreflective metallic layer stuck behind the rear polarizer.. to invert just remove the front polarizer and flip the polarization axis by 90 degrees. But this method of modding the front polarizer like that means wearing polarizing sunglasses will totally block out the display.
also modded the LED like this guy, where he swapped the default white LED with the red LED reminder light.
the LED light contact springs are small as fk and just nice i lost 2 of the 4... so my reminder light is non functional lol
my g5600 and 9100 gulfman both have dead battery and that 'burnt' screen.
the 'burnt ring' is from either the OCA adhesive or the acetate layer of the rear polarizer decomposing from age.
front polarizer aging usually results in just faded looking display despite a fresh battery.
i just mod for fun with the old ones laying around. plenty resources these days