this:
panicString" : "panic(cpu 9 caller 0xfffffe00240bdd88): FED err (perr_l1idat) on P-core: FAR=0x12e839408 ErrDet_Addr: VA=0x18165fe40 err_sts: (LLC_ERR_STS\/ADR\/INF=0\/0\/0 LSU_ERR_STS=0 FED_ERR_STS=0xf8000018165fe40 MMU_ERR_STS=0 DPC_ERR_STS=0) @rhodes_platform_error_handler.c:831
FED Error is fairly new, and the Internet has not seen much of it. Nor have posters here. The one user who reported that bullied an Apple Authorized Service Provider into changing the mainboard and the issue stopped.
The problem is that Apple First Responders are NOT trained to read panic reports -- that requires a Specialist. You want a Specialist, based on your report, to DIRECT an Apple service provider to change the mainboard (or provide an alternative that really fixes the problem).
What NOT to do:
DO NOT just submit your computer for service, COLD. They will run diagnostics in a loop overnight to all week, then return it to you "no faults detected".
what TO DO:
contact Apple support. ask for a Specialist to READ your panic reports. anything posted here can be read by them (which can be a big timesaver) provided you give them a hint about how to find it -- your avatar or a link to the discussion.
What they do not take at face value is our conclusions. They have their own more rigorous problem-determination processes.
Official Apple Support
