3.5 Ebay Screen Issues

[midgetman104]

Hey guys, I've been trying to hook up my 3.5 ebay screen

(I couldn't find my good camera as you can probably tell)
Anyway There is little pads on the controller board of the screen that I soldered to

But no matter what I try I can't get it to work, I gave it 5v and its recommended 12 volts. I know its not the mobo because it works on my tv just fine; Its probably not the screen either as it is brand new. Any Ideas of what I can do to get it to work?

 

[strangers]

Can you get a pic of the whole lcd controller, there may be some defect. Have you tried using a higher voltage yet? Also, try both video channels for lcd. You may also want to go back and check your wiring to the mobo, you never know. I picked up one of the 4.3" ones and didn't have any trouble, so it could just be DOA.

 

[midgetman104]

I have used the different channels, and I gave it 12v so voltage isn't the problem. Mobo Wiring is nice and clean. I'm really hoping that it isn't DOA, any other Ideas?

 

[superben51]

Did you share a common ground between the console and the screen?

 

[midgetman104]

I hooked up the screen to the regulators ground and when that didnt work i wired another wire from the composite video capacitor to the mobos ground

 

[superben51]

I'm pretty sure that the filtering caps, don't connect to ground at all.... Maybe try removing said wire.

 

[midgetman104]

yea that's what I was thinking, but I didn't no what else to do. K wire gone, but still nothin

 

[superben51]

Post some pictures of your set-up. You might want to include close ups of both the GC's video wiring and the screen.

 

[midgetman104]

I don't think the wiring is the problem, because I must've tried out a hundred different grounding methods. I think the problem is that the wires that came with the screen were connected to all these points but they went through a little black box that made it work. So I probably need to find another pinout that gives composite video, how would I go about finding alternate pinouts with my crappy old multimeter? Oh and Thanks for all your help superben

 

[superben51]

You could turn your multimeter to continuity and poke around. Also pictures, they will trouble shooting a hundred times easier.

 

[midgetman104]

Pics of the screen's controller board or my whole setup?

 

[superben51]

Everything, Some over view of your set up, Some close ups on each part, you know things like that.

 

[midgetman104]

K so took some pictures

I know its hard to see so I'll try to clear everything up.
+ 3.3v, 1.9v, and ground are going from regulator board to mobo
+two ground wires, and a 12v are going from regulator to screen
+ composite video wire going from screen controller board to composite filtering cap

 

[superben51]

Have you tried another video source or getting video from another point from the GC?

 

[midgetman104]

I haven't but I'm sure that this point is working because it was working on my tv right before I hooked up the screen