Hey there, I have been trying to fix the radio calibration problem which is not getting calibrated due to reasons I am unable to find yet. Here are a probable list of problems I have figured out. Please help me out flying my quad.

1. Wrong connection of FS R9B Rx with APM 2.6 board.
2. Wrong tuning of FS TH9X with Rx.
3. Any mistakes of steps followed during first flight setup.
4. Hardware problem.

Someone please help me out.

Mousum, welcome to RCIndia! 

Have you checked the receiver output using a servo or ESC? Does the radio calibration screen show proper stick inputs?

If the receiver is giving proper servo signals then check connections with the APM. If you have access to another radio set try it with that.

We can guide you better if you provide some pictures of your setup.

Thanks for your kind gesture sir. Ya I have checked connecting esc with the receiver, but it did not work. Is it a hardware problem ?

Have you completed the binding procedure of the transmitter and receiver? If yes, try controlling a servo with the receiver.

Y binding is done. I tried connecting escs without apm board.Dint work. Connections and all were correct. Have to check using servo.Can you provide me your mobile number sir ?

I can't help you much over the phone without seeing the setup. Why don't you post pictures of your connections and screenshots from mission planner. That way others will be able to help too.

Here is the setup of my quad. Image attached...I have done calibrations like compass, accel and all succesfully...But radio calibration was not done...red sticks were not shown upon changing the Tx trims and switches to max n min positions...

Get a closer pic of just the APM and rx.

I did the radio calibration in the same setup without much problem. I am also beginner. You can see the thread http://www.rcindia.org/multirotors/building-apm-2-52-quadcopter-with-st360-kit/ where I have posted the relevant videos using which I have managed to calibrate the radio successfully. In fact it was easy..only calibrating the Auxiliary channel requires some patience.

Inputs 1-4 in APM goes to channels 1-4 of the receiver. That is apparently ok in your setup. Can't see the signal and earth wires clearly but if signal wire is upwards in the Rx and inwards in APM then its ok.

Wrong tuning should not happen with the default setup of the Tx. Did you change anything there?

How do you know that binding of Tx and Rx is ok?

This implies either a faulty receiver or improper binding. Just try controlling a servo and the problem will become clear.

Binding was done with proper steps  taken...red light of Rx blinks constantly once binding is done...

Closer view attached

Dear sir,, there was one more major problem that I faced...that is my apm 2.6 board is not powered up by USB only...so I had to connect the power module...so is there any problem in my board ??

That's not how it should be.

The red light blinks rapidly in binding mode, and once the binding process is completed, it should stay lit .

Oh yes,,,I did that properly sir...but why my apm 2.6 is not getting powered up by USB ?  It needs the battery to be powered...

Now, you may try it like this ;

Connect a ESC cable directly to Ch3 on Receicer.
Connect a Motor to ESC (no prop )
switch on transmitter, keep the throttle stick low .
Power the ESC with a LiPo.
Check the LED status on Receiver and post the result (Check whether the Red Led on receiver is solid) .
If the red Led is solid lit , apply a little throttle ,and the motor should start (If esc calibration is already done)

Do the above steps, and post the result.
By the way do you have a Servo with you ?

APM should power up just with a USB connected.
detach any other connectors from APM, and connect USB, check what happens. also check your USB cable (Check with another cable if you have spare.)

Yes sir,,i did that...everything worked fine...led lit solidly...throttle applied...motor worked...

Ok now, receiver and radio is confirmed to be working fine, No more worries about that.
What happened with APM ?

Nope sir,,,its not working on USB anymore...So wat do i do now ?   To power it I must have to connect Lipo...thats the problem right now

Did the APM work before with just USB?

Try with another USB cable, and also try connect to another port on PC.

No sir,,,it never worked with USB alone before too..I have tried other USBs and other ports,,,other systems too,,,

Maybe the USB port is damaged. When you power it using a LiPo, can you calibrate receiver input now?

No sir,,,I tried,,,I am using factory settings on Tx which is in Heli Mode1 PPM...Rx & Tx are binded...but during radio calibration on Mission Planner the roll, pitch,yaw and throttle values are not getting changed...accel and compass were done and also firmware installed successfully...should I do any change in factory settings on Tx...should i make it Acro mode or wat else is the problem sir ?