BTT Manta M8P with CM4 connected to BTT Pi TFT50 V2.1 display

[Kaye7877]

I am attempting to change from a 12864 display to a BTT Pi TFT50 V2.1 display.  When I connect the display up to the M8P Manta's DSI port on the back of the card, the CM4 will not boot.  If I disconnect the ribbon cable, all seems to be working fine again.  I also have a BTT Pi TFT43 display and it does the same thing. So, that means to me the problem is how I am hooking up the cable, something on the Manta, or maybe a missing jumper?

I am connecting the cable with the copper pins away from the board on both the Manta and the screen.  I would love some help or direction on how to resolve this problem. 

 

Brad

[Kaye7877]

Got it.  I didn't want to take a change to burn something up by reversing the ribbon cable.  After digging out the schematics for everything, I figured out the ribbon cable exposed copped needs to go towards the board on the BTT Pi TFT.  Problem fixed.  I a little surprised something didn't get damaged.

[Navid]

It's funny seeing your post! I have a M5P that I was trying to hook up to the same display. Same problem as you, and as the M5P was new I assumed it was defective. Using my voltmeter I noted that the cable (without the display) showed 3.3v on the ends, but with the display only 0.85v. Went back & forth with BTT without resolve (they accused me of damaging the board), until I accidentally swapped the B-FRC with an A-FRC. SOB worked! That's when I figured out the problem - as you did. Came across your post afterwards while looking to see if anyone else had noted this. 

BTT makes great products, robust, clever, and very useful. Unfortunately their documentation and installation details leave much to be desired. Hope they can get their act together before someone else steps up.