I have been having some super weird issues with 4-in-1's lately.  The first one was a Mamba 50A - ESC #1 would not work in Betaflight, nor would it be found in BLHeli32.  Newbeedrone wanted me to take photos and were taking forever to get back to me, so I got a 55A version from Pyrodrone in the meantime, which arrived today.  I soldered ONLY the leads this time, plugged into a *brand new* flight controller (I've tried a couple already), and this NEW one also won't show any ESC in the ESC #1 position. 

I am really at a loss as to what is going on here.  Both 4 in 1's read ESCs #2, 3 and 4 just fine.

What version of Betaflight is on those quads?

(28-Dec-2021, 01:06 AM)SnowLeopardFPV Wrote: What version of Betaflight is on those quads?

Same quad, different ESCs.  Betaflight is on the latest version for the board (also a mamba) - 4.2.11. I've also tried three different harnesses.

EDIT: I should also add that I tested continuity between the positive and negative leads against all three motor pads on ESC1 and got no continuity.

Try downgrading to Betaflight 4.2.9 and see if the issue then resolves itself.

There was a DSHOT protocol bug introduced into Betaflight 4.2.10 that was supposedly fixed in Betaflight 4.2.11, but maybe it still isn't fully fixed. Going back to 4.2.9 will help to either confirm or eliminate whether there is still an existing bug with that in 4.2.11.

(28-Dec-2021, 01:27 AM)SnowLeopardFPV Wrote: Try downgrading to Betaflight 4.2.9 and see if the issue then resolves itself.

There was a DSHOT protocol bug introduced into Betaflight 4.2.10 that was supposedly fixed in Betaflight 4.2.11, but maybe it still isn't fully fixed. Going back to 4.2.9 will help to either confirm or eliminate whether there is still an existing bug with that in 4.2.11.

Just went to 4.2.9 and no luck.  Still get a red "100%" in motors tab and BL32 won't read ESC 1.

I just found something, I believe - with the harness plugged in, I get continuity between the GND and S1 solder pins on the 4 in 1. Unplugged, I get nothing.

EDIT: This is also happening when I plug the FC into the other problematic 4 in 1.

And I just checked the FC without any harness - S1 seems to be shorted to GND somewhere in the board. I know I could try remapping the signal wire to an LED pad but this is a brand new board. Maybe RDQ will send me a replacement.

Ok - another question. I've altered the harness so signal 1 goes to LED. Under resource I see three LED references: LED STRIP, LED1 and LED2. There are 2 LED pads on this board. I've tried remapping motor 1 to all three of the LED references and ESC1 still does not read. However, I'm now noticing that there is an area that reads "MB_LED" and "BF_LED", and it seems to require bridging to one of the two. It appears to be bridged to the MB_LED side. Should I mess with this?

https://imgaz2.staticbg.com/thumb/large/...0.png.webp

EDIT: Nevermind, I figured one was Mamba LED and the other was BF LED. Bridged the BF LED, remapped the LED STRIP and it worked! Now I find the FC was the problem all along and I have multiple, perfectly good 4 in 1's.

Sorry for talking thru this out loud, but maybe it'll help someone down the line.

Out of interest, what model of Mamba FC is this issue happening on? I wonder if there is just a bad batch of Mamba FCs.

(28-Dec-2021, 10:48 AM)SnowLeopardFPV Wrote: Out of interest, what model of Mamba FC is this issue happening on? I wonder if there is just a bad batch of Mamba FCs.

This particular one is a F405 DJI. I had the same thing happen (albeit after a crash) where ground shorted to motor 2 on another Mamba F7 board a few months back.

I ALSO just had to return a Mamba F7 DJI as the MCU would get burning hot off of USB power out of the box. I don't know if they are having QC issues or what.

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UPDATE...

Well, I smoked a Fettec G4 now. I connected it to the Mamba 4 in 1 and it worked fine, aside from motor 1 not working. Swapped with a new motor to test and the whole board is now dead.

These Mamba 4 in 1's have smoked or damaged 5 boards now in the last few weeks, and I am 100% certain it wasn't my wiring, as I did continuity checks out the wazoo, plus the boards DID work for a short period. I'm switching to a full Fettec setup because I know they'll play nice together but I am really turned off on anything Diatone now.