Second screen not working, bad Pi?

[Brohvis]

Please help me guys, I'm at my wits end. I first tried utilizing the BW screen. As I'm a soldering noob I assumed that I had burnt it out or something and ordered a gearbest. Still no luck. I've tried multiple wiring diagrams and tutorials and I just can't imagine what the issue could be at this point.

Hardware:
PI Zero W
Gearbest Screen (with and without 5v mod)
BW Screen (with and without 5v mod)

Issue:
Screen does not show input or light up at any point

Mini HDMI out working 100%. Have attempted to edit config.txt before and am now running a stock retropie build.

[YaYa]

Did you try to power the screen before starting to open cases etc. ? Plug it to video source, power input and switch on, just to be sure that it's working ?
Also, those screens won't power if no video is thrown into them.

[dryja123]

Pictures on how you wired the screens to your pi will help.

[Brohvis]

Yeah I figured. Didn't have a video input to test with unfortunately (got rid of all of my composite devices a while ago). Might have a VHS/DVD player in storage.... will post wiring pics in a little bit. In the mean time my current wiring: I have my yellow in rca video out on the pi, red (power) (with or without jumper) is in my powerboost's +, and ground is next to my rca out on the pi, just to its left. Have tried direct to pi power, ground in several places, and now two screens. I swear I saw it flash a little last time I was messing with my ground but haven't been able to replicate.

[rodocop]

Yeah, without pics there isn't much we can do to help. With the gear best screen, there are two variants that I have received. One needed a 5V mod, the other did not. I'd be curious which board you received.