white screen after reflow

[bjpurdy]

I and a friend purchased a couple of your mintypi v3 pcb kits last summer, and we are just now putting them together. Mine went together great, but we’re having an issue with the screen on my friend’s build. LCD related GPIO pins are getting continuity all the way from the pi to the lcd board, but when we power up, the screen stays white from power on all the way through the boot process. I plugged his button pcb into my screen, and everything boots up and works fine, so I believe his pi and sd card image are fine. We reflowed his screen ribbon cable until I am very satisfied with the solder job, but still getting white screen. Power to the lcd board is showing 3.27V. I’m planning to just take my screen out and give it to him to get him up and running (he’s in high school and I’m 37), but I’d love to fix the other screen if possible. Any ideas on how I might proceed? Awesome project, by the way. Having a blast working on it.

[dryja123]

Sometimes the screen needs a few reflows to get good contact. The early screens that went out were poorly soldered to the board before Helder caught it. Try reflowing it again with a bit of flux.

[Helder]

I have spoken to this person through email and the problem will be resolved once he is in the states. It's likely misalignment of the LCD which is what was the issue when we tried to reflow the pins of the ribbon, some times they'd be so far forward and looked like it had good contact but it didn't.

Only way to fix it is to remove the 51pin ribbon without damage (I have tools for this) and re-seat the ribbon properly then solder it back on.