So i have an ender 3 printer with bl touch auto leveling and the creality 4.2.7 silent motherboard. As mentioned in the title, i started a print but forgot to check bed clips holding my glass bed on were positioned correctly, i jumped when i heard the awful grinding noise of my nozzle stuck on the clip, immediately flipping the power swtich to kill the motors. Unfortunately ive had these sorts of issues all the time, usually can power down, find the issue and then restart. But this time when i went to power the printer back on, all my steper motors atarted making a whining/grinding sound without moving and the screen never went past the blank boot screen.
That could break a motor (motor pinions) but crashing the firmware ? 
Have you tried to reflash it ?
Yes, tries the same and a renamed firmware file, using the same sd card i already uploaded several versions of firmware before. Also checked to see if motor spindles were spinning inside gears but all are just vibrating loudly
not turning but vibrating ? Not going to lie but I think this printer got some serious damages then
You may have to replace every damage motors and if I understand correctly, reflashing the firmware didn’t work ? That could mean the motherboard got damaged too ! (power surge due to forcing motors I guess ?)
I think I kept my Ender 3 for nearly 5years before breaking it so yours (even older ?) was collector ! 
Yes, they sound like a fan slowly spinning up in sync, whats wxtra weird is i can still turn them by hand between the pulses. And also correct, relashing firmware made no difference, screen wont change from an empty blue screen. I unplugged all the motors and let it sit on the the firmware sd card in it to try and give it more time to flash without my motors making sounds of death but also no joy
Could custom firmware settings slowly have been damaging the motherboard or stepper motors because of bad settings?
Generally not. It could reduce the lifespan if it’s pushing accelerations and speed to max but that’s not what I would call “damaging”. Here, it looks like a power surge….I think you may have to change the motherboard first and then check if that fix it. (Motors could not be working due to the non-booted firmware) 
If you’re planning to repair and once you’re sure the motherboard is working well but not the motors, I suggest this video : Service tutorial Ender 3 series motor troubleshooting
I was thinking new motherboard too, but rn my funding is a bit low. Guess ill get it as a Christmas present to myself later 
and mine is about 5 years old itself right about now. Already sent one motherboard to electrical heaven in a cloud of smoke. (Im really hard on it trying to learn how to troubleshoot everything myself, but i was fully stumped this time)
Out of curiosity would anyone be able to help me figure out what the different LEDs on the motherboard mean?