Black Screen [Guide 03]

[Fleder]

but still you need a power source.

Yes, I can buy it in a shop ? 5V will be good, isn't it ?

No, that is the catch.
It either will run with 5v or 12v as indicated and intended.
For 5v, you can try to power it with an old USB cable which you solder onto it.
If this does not work, you either have to modify it, or it does not work at all and you would have to buy a Step-Up module, or another dosplay.

[AlexKidd2]

For 5v, you can try to power it with an old USB cable which you solder onto it.

Ok, don't have USB cable but I will get one. There is a red cable in it, I suppose ?

If this does not work, you either have to modify it, or it does not work at all and you would have to buy a Step-Up module, or another dosplay.

Ok, but why with you with the same screen it works, and in my case I should buy a Step-Up Module ?

[Fleder]

Usually, USB Cables have 4 wires: red, white, black and yellow.
Red for + black for - and white&yellow are for data, i think.

No, you only need a Step-Up Module if your display does not work with 5v and can not be modified to run with 5v.
If it works out of the box, great, if it does not and can be modified, okay, but if it can't be altered to accept 5v only, there you go.

[AlexKidd2]

@Fleder I tested with a USB cable but it didn't work... But it should, no ? Because you, you succeeded and we have the same PCB...

I precise I soldered only the red, the yellow and the white (and not the blacks, for -), but maybe I should ?

So, if you can advice me, maybe for a step-up module it could be cool... Thank you

[SidSilver]

The black goes with the red. One without the other and you don't have power...

[AlexKidd2]

Thank you Sidilver, I tested but nothing happened...

[SidSilver]

Sorry, I realize that what I told you was not clear.
I don't know your skills level in electricity.

What I said was : the black doesn't go on the red, but if the black isn't plugged on the Gnd pin and the red on the 5V pin, it won't work.

[AlexKidd2]

Ah, so I did a mistake... I will try later... But thank you !

[ptitneo]

Yo AlexKidd2,

I think I figured it out. The white wire on the Pi's composite out is GND, the other being signal. But you wired them to AV1 and AV2 on the controller board. That's the issue. The PI's signal wire should (square pad) go to either AV1 or AV2 pads (where the yellow and white cables used to go), and the GND wire (circle pad) on the pi should go to your GND on your controller board (where the black cable is).