I've now owned a QY300 three times. Its a fantastic tool with one glaring flaw.
You need to be hunched over it to see the screen and the lighting has to be perfect if you don't want reflections masking crucial information.
About a year ago I bought a replacement screen with a backlight and then proceeded to do nothing with it until today (technically it's actually Black & White, but it appears blue off angle and on camera).
There's not much info out there on replacing the screen with a backlit one (just this gallery), so I was a little shy about getting started. It turns out that I needn't have worried. Its a fairly simple procedure. I didn't even have to mod the case.
Its the middle of COVID-19 lockdown number two in Melbourne so I couldn't run out to the shops and get a new header, so I had to resort to desoldering the old one. Not the worst task, but kind of annoying and I'm out of practice.
The header on the old board had 20 pins, the new one has 22. The extra two pins are for the backlight.
The old header does cover up those pins, but that was easy to deal with as the LCD replacement that I used had another point that was readily accessible for soldering on some power leads.
I could probably have just made a voltage divider to power the backlight, but I happened to have an already assembled voltage regulator kit and there was space in the chassis, so in it went.
