Very cool find here: Ender 3 V2 Schematic for 4.2.2 board · Discussion #814 · Jyers/Marlin · GitHub
PDFs also attached here for reference
Creality.4.2.2.-.Schematic.28-5-22.pdf (188.1 KB)
Creality.4.2.7.-.Schematic.28-5-22-1.pdf (193.7 KB)
In addition the 4.2.2 board apparently can come with different driver chips:
Creality V4.2.X Board Driver Codes
The letters written on the card reader slot (with marker) are different depending on which stepper driver it has.
These are for the ones 4.2.X board with STM32F103RET6 controller:
C = HR4988
E = A4988
A = TMC2208
B = TMC2209
H = TMC2225
Credits to the folks in the above link. Must have been an insane work to establish these schematics.
Beware, probably due to the chip shortage, newer Creality boards use silent steppers only on X and Y, but use A4988 or similar “loud” steppers on Z and E. I am not sure whether they have two letters on the microSD slot, but keep this in mind
FYI, I do have 2 letters on the micro sd. Rc.
Nice to see this info in one place. Creality are a real pain with their boards. You can also add A/c to the list, that is what I’ve found on the V4.2.2 boards in the E3 Max. They have silent TMC2208 on x&y then I think it’s HR4998’s on z&e although it could be A4988 or any other random chip they have to hand.
I’ve also seen T8 and GD on the SD card shield. In a chat with Creality I asked about all these and was told it’s just something that’s jotted down in the factory and doesn’t mean anything, so that’s really helpful.