Pine A64+ vs LCD do not boot

[pfeerick]

Since it's the power light that's going dim/half brightness, it sounds either there is something wrong with the LCD or the PSU. It's not a 'smart' indicator or anything... it's connected across the power lines, so directly shows what's happening with the power to the pine64. i.e. going dim means the voltage is dropping, which is not good. I'd double check it's plugged in the right way... not staggered/out by one pin, etc... And  if you're using the microUSB connection there's a good chance the pine64 board isn't getting enough power to run properly with the LCD attached - that's why later revisions of the board switched to a barrel connector, and people were advised to power via the raspberry pi header where possible. But I'll leave it to someone who has actually used the LCD with the pine64 to problem solve this with you further!