Hi ph4 pro had to ne replaced the 3-1 board, the guy that did this said that it's because of the gb size of micro sd, anyone know if dji made a project mistake and you have to use only 32gb micro sd to the 3-1 doesn't break?

I use 128GB cards all the time with no problem.

Hi, OMNIDRONE. Thank you for reaching out. Recommended microSD Cards for DJI drones have been tested first before we release a list. Upon checking the list for Phantom 4 Pro, you may use 32GB up to 128 microSD Cards so there's a high possibility that it is not what caused the issue. You may also refer to Mr. Strat's reply above as a reference. I hope this helps. Thank you for your support.

DJI Gamora Posted at 4-8 19:43
Hi, OMNIDRONE. Thank you for reaching out. Recommended microSD Cards for DJI drones have been tested first before we release a list. Upon checking the list for Phantom 4 Pro, you may use 32GB up to 128 microSD Cards so there's a high possibility that it is not what caused the issue. You may also refer to Mr. Strat's reply above as a reference. I hope this helps. Thank you for your support.

Specifically, I use Sandisk Extreme 128GB cards in both my Phantom and Mavic with no problems.

Mr. Strat Posted at 4-9 19:05
Specifically, I use Sandisk Extreme 128GB cards in both my Phantom and Mavic with no problems.

Hi there. Regretfully, we won't be able to diagnose what caused the issue remotely. If you want to know which caused the issue, you may send it to our repair center for proper diagnostics. As for the microSD Cards, here are the recommended ones for your drone:

I use a 256 gb in my P4P and have no issues.  It recognizes the full card size.  I use Sandisk Extreme Cards.