My lab power supply display slowly turned black during the last few month...:
It is an old design and OK after all those years, but why does this process happen? I once had an LCD watch and when sitting in the sun outside all of the sudden it turned black.. was very hot, bought a new one. This thing has not been hot.
So, anyways had some other ones that did not fit, had a different driver, did not want to re-write the software, thing is way too good, so ebay: found a Geeetech Yellow backlight LCD 1602 16x2 Characters display that claimed to have the same driver chip, and same mechanical outline, start bid was 99 cents, so I did and got it, shipping 1 dollar. Installed it yesterday. Works perfectly, OR??? WOW such a bright backlight, blinding, switched it off again. Checked the datasheet, maybe it needed a series resistor ?? Nope, 5V on the LED pins, resistor is on the module. Still could not believe it, looked like a reading light, measured the current:
10 mANow you guys talk about LED aging, but it seems the newer ones are so good, those need attenuation. Added 270 Ohm in series, now it is OK. It is still bright in the evening, but no eye damage this way.
For new designs I only use OLED.