Yeah. Then you need to change the settings. Probably in a lot of places.
You need to go step by step through the setup of the 7200BX and the Tx channel reverse settings, as described in the 7200BX manual.
For this collective servo direction issue:
Enter setup mode on the 7200BX, go to setting I. Then change the setting one step at a time and move the collective up/down until all the servos are moving in the same direction (not necessarily the correct direction, that's the next step).
If you see that up collective/throttle is causing the blades to tip in the wrong direction (on the 300X the controls are trailing edge, so up collective will move the swash down, and vice versa) then reverse the pitch channel direction on your Tx.
You may also need to change the M setting (swash sensor directions), follow the directions in the manual. Basically enter the setting, then tilt the heli forward/backward and left/right and the swash should tilt against the direction of the heli tilt (appear to stay level to starting position). If the swash tilts in the direction of the heli tilt then you need to change the setting until it goes in the correct direction on both forward/backward tilts and left/right tilts.
Check Tx cyclic direction control too. Stick right should tilt the swash right, if it goes left reverse the ail channlel. Stick forward should tilt the swash forward. If it goes backward, reverse the elevator channel.
You also need to check your tail sensor direction, tail endpoints, piro optimization setting, and Tx rudder reverse setting.
Like I said, basically a start from scratch check and set everything exercise. It sounds like the new servos are reverse directional control compared to the stock ones so the defaults will not cut it. You need to go through and set it up from scratch without reference to default settings.
