ADC level tolerance of [Power Socket]

Dear Hardware Doctors.
I think that ADC input of [power] socket of my pixhawk is dead.
From the very begining of my adventure with pixhawk, I got strange behaviour (frequently in mission planner i could not set up battery monitoring, or sometimes succeed, but after some time MP now says just on battery monitor “this feature is not enabled in your firmware”. And that’s all my fault, because AFTER situation is so bad, I started to look on hardware.
Seems that my 9,6V battery, which is connected to simple power module , on voltage sensor output pin is 1/2*BattV , which is higher obviously than allowed 3,3V
And occasionally I had there ~5,5V
Here I comes slowly to the end. I added voltage divider to power module, now with full battery I have there 2,7V, which is fine. But I can not see any values in MP, so probably ADC on this pin is dead.

Is there any way to look on real ADC input values? if it is NuttX shell, then I tried to connect to console 5 using FTDI USB 3,3V cable, but not succeed.
Is there any other way to see ADC’s? All other functions of pixhawk looks OK… only power module ADC are blind.
I read on wiki that nuttX console shoul be available via mavlink, but how to exploit it? I am using mission planner only…

My problem was related to software. It is solved, but anyway the question formn me is still not answered - what is ADC max level on [Power] socket.
somehow all cheap power modules are Vbatt/2 , and lot of machines use 3S batts.
So is it really 3V3 max?

anyway - luckily for me - it was not burned by 5,5V , but now I added additional divider so 2,7 V is max…