third ESC in about six weeks. im losing my mind. its a 4in1 30x30 running 4s, motors are 2207 2450kv, and i keep getting the same thing ? flies fine for a session or two then one corner just dies. not all four, always just one motor channel. i thought the first one was a fluke, second one i figured maybe i shorted something during the build, but this third one going the same way has me thinking there's something systemic i'm missing.

soldering looks clean to me, i used flux, joints are shiny. i'm running XT60 with a 35v capacitor on the battery lead. the only thing i can think of is maybe my battery sag is worse than i think and im spiking over the ESC rating but even then i wouldnt expect it to always be the same corner. its the back left motor channel every single time which is just weird. motor itself tests fine after, its definitely the ESC dying not the motor.

running betaflight 4.4, motor output is set to Dshot600. temps dont feel crazy hot when i land. what am i missing here

back left being consistent every time is the real clue here. that sounds less like electrical overload and more like a cold joint or a hairline crack somewhere in the trace under that specific FET. have you tried reflowing that corner specifically? sometimes it looks fine visually but there's a micro void under the pad that only shows up under load. if you have a microscope or even a loupe its worth a close look.

also what ESC brand is it, that matters a lot. some of the cheaper 4in1s have genuinely thin copper pours on specific channels and they just cant handle sustained punch-outs on that corner depending on prop wash.

dshot600 on 4s with 2450kv motors is fine but are you running bidirectional dshot? cause if RPM filtering isnt set up right youre gonna be running way hotter than you think. ive seen people blame ESCs for months and it was just the filtering making the motors fight themselves constantly. check your blackbox logs and look at your motor outputs, if theyre all over the place thats your problem not the solder joints.