I have a Ender 3 pro with a sprite extruder. Also upgraded to the 4.2.7 board.
Problem is my extruder will stop randomly. I have replaced the main board twice, cables, even a new power supply. Even tried a different motor nothing works Sometimes the Extruder will barely move, just barely jerk. Thats all. Everything else is works fine. Then just out of the blue it will start working again for a while. The printer is plugged in to a ups. So, I don’t believe it’s bad voltage.
I think it may be out to make me go insane trying to figure it out. Oh this last time it stopped extruding I was running Klipper on it and reflashed Marlin. Still the same not extruding.
Hello @kerma314
Welcome to the Creallity Forum Community 
Have you tried running the printer without the UPS attached. Just wondering. You never know… 
Then there is always a chance that the stepper motor is faulty… 
I would also recommend checking the voltage selection switch, if you live in a country with a 110/115v mains supply you will need to flick the voltage selector to the 115v position.
Good luck!
Just tried that no change
Yes it is set right at 115v.
Check the main pins into the board. Make sure they are all the way in.
checked the continuity of my extruder wires all good. Reseated extruder wire connections. Took the extruder off the hotend so no resistance on the motor. Set it to print but no reaction from the extruder stepper motor. All the other stepper motors work fine.
Can hot swapping stepper motors damage anything?
Have you switched that board out with another to see if the problem is still there. I know you said you replaced the main board twice… Not sure which one though…
I got two 4.2.7 boards off from Amazon. Both board give me the same errors. Then I change out the power supply with a new one. Still the same problems.
Well I come to the conclusion the mainboard must be fried. So instead of taking a chance of wasting $40 on a new on. I just bought me a new Ender 3 V3 SE. Has all the upgrades I wanted. For me a great printer. The old ender 3 well wait until later.
A new Ender 3 V3 SE… nice… I was just reading about that one… Got some good upgrades on that printer…