480 Screen Question

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Sep 30, 2021
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I just got the recommended 480p screen in today and when I went to put it into my portable I determined that the pin circled in red should be connected to 5v and the one in yellow should be connected to ground:

Photo on 4-17-23 at 3.07 PM 2.jpg


Wired it up and nothing! I checked and it seems that all three of the pins are grounded. I feel like that is not normal but I am not used to working with barrel jacks, so I am not sure. I checked a few other finished projects using to make sure I had the right pins connected and they seem to be the right ones. I've had way too many driver boards burn up on me so I'm nervous to go on without a second, more qualified opinion.

Any help is appreciated, and I'm hoping that I didn't just pay for a faulty board
 

CrazyGadget

Crazy Helpful, CrazyGadget
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You're right with where 5V and Gnd go, no issue there... Have you double checked around the board that there are no solder splashes or other shorts? And are you sure you put the ribbon cable in the right way?
 
Joined
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Location
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Ok so I figured it out

I was curious where the short could have possibly been, so I cut the trace leading from the barrel jack to the step down converter. Upon probing I learned that it was on the side of the step down converter. Along that trace was a resistor, circled here in purple:
Photo on 4-17-23 at 3.07 PM 2.jpg


I removed that to see if that was the one causing the short and that was the bugger. Resoldered on, tested resistances, attached a thin magnet wire to bridge the cut trace and bam! No more short. We got the screen working now.

Thanks @CrazyGadget if you wouldn't have suggested to check for solder splashes I wouldn't have pulled out the microscope to inspect every friggen tiny connection point on the board, and wouldn't have come up with a solution
 
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