[g0tjh]

No its not that as i have disconnected the FC   it is just  radio > rx > esc > motor .
they came as a kit ...no making no info nothing . i have been watching loads of u-tube videos to see if i can hear
the same tunes n bleeps as my ones ,,,,not found one the same as my ones . i will cut the shrink off one and look at the chip set that may be a give away . also i will e-mail the guy i got it from to see if there is a fix .
it is odd that with the FC in ,and the output test they all work just fine (they start with no kick in that mode).
if i could find a way of reading out the settings ,i would set them all the same

[TheOtherCliff]

output test again all spin up ,,,,,but if i then arm the motors ,only 2+3 spin

Is this still true?

What is unusual about this copter?  I assume it is a quad, with PPM/PWM/DSM/SBus input and that you have at least tried PWMSync for the ESC protocol.  What configuration did you specify during setup wizard and what things did you change after that?

Are you using OneShot ESC protocol perhaps?  I would suggest that you try PWMSync for the ESC protocol, and set all output banks to match that.  At least for a test.

Do you have any other FC's to test this on?  Make sure to save settings to a file so you can restore.  Have you used this FC successfully in the past?  What changed since then?  Crash?  Upgrade?  New model?

What are the markings on the big chip in the middle of the top of the FC?  There are some cloners that put the wrong chip there.  It does not have as much memory.  It might be able to fly other firmwares, but not OP/LP.