[TunerX]

I bought my first CC3D board for my first quad and it had some issues such as no bootloader or 'bad' firmware... they all were solved and the board was running good. but recently I had a crash while tuning it after which i was unable to connect the board to my PC to reconfigure it.

[TunerX]

I bought a CC3D board for my first Quad X250.... initially it had some issues such as no bootloader or 'bad' firmware. all were fixed and it took off. recently while tuning the quad, it had a crash. now the board is not being recognized by my PC.
 When I connect my board to my PC, it shows a "Device not recognized" message. it won't even show up in the GCS. The blue LED stays off, and the green LED flashes 3-4 times and it also goes off.
but when i connect the battery, it works normally. and also flies... but poorly.
what might be the problem... please HELP!!!

got one more issue.
in almost all the videos about PID tuning i have seen, everyone has their P gains at around 50 and their quad oscillates at around 60-70 P gain.
but my quad oscillated at P=20... is there anything wrong with my quad? or is it okay?
I'm flying in attitude mode.

[TheOtherCliff]

You have proven that the board is damaged.  Spend some time trying to find and fix the problem (cracked/broken connector/trace/component) or buy a new board. 

If you can't run "normal" PIDs, then the first question is what ESC protocol you are using.  You should run at least PWMSync or PWM @ 490Hz.  Make sure it is set to that on all banks that connect to a channel that have an ESC (or just all banks).