tft screen controller board on 3.3v ?

[Lumoo]

so i recently began gathering parts to make my own GB|Zero following the forum posts and similar i bought a 3.5 tft screen +controller board and fitting ribbon cable

i ended up with this
https://www.dropbox.com/s/xosicfh7i15cj ... 7.jpg?dl=0 (back)
https://www.dropbox.com/s/m1prqkc33hn8x ... 2.jpg?dl=0 (front)

following the already existing information i figured the soldering path for using the 5v

but iam very curious as this board allows the use of a 3v3 connection as seen on the back aswell as the punchtrough holes to solder on directly
does anyone have any clue wether or not i can use this to directly feed the screen from it ?
if i can it would save me a ton of energy spend to keep the screen working resulting a longer lasting battery (or shorter no idea)

i got it from gearbest
https://www.gearbest.com/development-bo ... 29447.html
for anyone intrested

[moosepr]

Well the nominal voltage of the average lithium rechargable is 3.7v, so if your screen can run from 3.3v your way closer to begin with. Boosting to 5v just to drop it back down again is of course wasteful. I would say give it a go! You won't damage anything by under voltage!

[rodocop]

Hmm. Couldn't hurt to try it with 3.3v see what happens. Also. I've used that same screen 4 times and have not once had to mod it to work on 5v. Did you try it before you ran the wire? Mine have always worked with 5v out of the box.

[tinkerBOY]

I have the same lcd board and i have tested a 3.3v power supply with it and it works fine. Not from the back though but directly to the output pin of the 3.3v regulator.