This might seemed repretitive to people but...

I've just recently got a second hand P3 Advance. It flew perfectly tens of flights already.

But then I got a phantom bag, and the prop guard attachment didn't fit with the drone.

I removed the prop guard, and not having the original screw I used the long ones

I started the drone and try to CSC start up the motors, I got the ESC error warning.

*here's the deal, I live very far far away form a service center and would rather want to fix everything myself. I know that it's either the motors or the ESC that's messed up according to some research but wanted to know either to buy new motors or new motherboard. Is there any way to possibily know?*

**any other easier troubleshooting will be appreciated*

I'm guessing the longer screw is your problem. Not sure if you have damaged the motor or not. Take that long screw out and see if the error goes away. If so, you are probably ok. If not, you may have motor damage. If it is ok without the longer screw and you don't have the original, grind the long one down to the proper length.

The longer screws are provided with prop guards to account for the extra thickness of the guard.  If you take the guards off, you can't just screw the long ones back in without a "washer" or other additional material.  If you do, the screw will penetrate into the motor further than intended and will eventually hit the enameled wire of the motor windings.  If you are lucky it will just stop and not damage this insulating layer of varnish over the copper wire.  If it does damage the insulating layer, you risk having the motor windings short out, which will potentially cause the motor to fail.  If it is a bad short, the load on the ESC could be great and could cause that to burn out as well.

If all the motors spin up, it is likely that the main board is OK, but you should change over the motors due to unknown internal damage, and make sure you use the right screws next time.  It's not worth leaving a damaged/unknown motor in there as it could fail in flight.  If one or more motors don't spin up, then the motor at least is damaged.  Once they are replaced, you will be able to see if the main board needs replacing too.

Hmmm I put the prop guard back on since I do not have any shorter screws. Still the ESC Error warning persisted and non of the motors are spinning up so I do not know if it's the motors or the board that's failing me. Is there anyway to narrow down the cause before buying parts? Thank you anyways.

VoridaBunny Posted at 2017-5-12 00:47
Hmmm I put the prop guard back on since I do not have any shorter screws. Still the ESC Error warning persisted and non of the motors are spinning up so I do not know if it's the motors or the board that's failing me. Is there anyway to narrow down the cause before buying parts? Thank you anyways.

You have probably damaged the motors with the longer screws
If that's the case they're not expensive to replace(around 18$ a motor)

VoridaBunny Posted at 2017-5-12 00:47
Hmmm I put the prop guard back on since I do not have any shorter screws. Still the ESC Error warning persisted and non of the motors are spinning up so I do not know if it's the motors or the board that's failing me. Is there anyway to narrow down the cause before buying parts? Thank you anyways.

Can you turn the motors freely with your fingers?  If they don't move, the screws could be super long and mechanically crushing the windings and binding the insides of the motors.   Try to turn it on and run it at idle after removing the long screws.  Some prop guards only use 2 screws per motors, but if you have to remove all 4, be careful.  Don't have props attached.  You will get "prop missing or loose" warnings in this case, which is normal.

Yes the motors are still turning freely with my fingers. It's a 4 screws type. Yes I tried it without the prop attached. One more worries I've got is that I just realized there were no start up sound (4 da-da-da-da beeps) as well. Does this mean the ESC is actually fried?

Those long screws hit the windings & your motors are toast, so you could try just replacing the motors first.
If she fires up okay, then you get away with just buying new motors.
My buddy, did same as you, took guards off & mistakenly re-used the long screws, got the ESC error warnings, replaced motors & all is okay.

They tell you in the guard instructions to be sure and save the original screws because the long ones without the guard are long enough that they hit the motor, not allowing it to turn.  At least my instructions said that.