hi,
im designing a tricopter.i have all the components,loaded the firmware for tricopter in the hobbyking quad board v2.but when i try to arm the board its not arming,a few blinks of led is coming and then after a few seconds one blink of the led is coming.nothing else.anyone know how to arm it please help me.im using a flysky 9ch tx mode 1

i am not sure but as you said it's mode 1 bring right throttle stick down-right corner to arm motors.
Led on - armed
led off - disarmed

Follow the instructions from the manual, including using additional trim if needed.  I had to do this couple of times on my V1 board.

Remember that if you had to "reverse" the channel used for arming, you will have to push sticks in the opposite direction from what is mentioned in the manual.  I have mentioned this before :

http://www.rcindia.org/self-designed-diy-and-college-projects/quadrotor-build-thread/msg68736/#msg68736

today i tried the firmware...finally its working with the 1.6 aero firmware,but its not arming with the higher versions..anyways im happy with the 1.6 version,will fly the tricopter in a week..

and my suggestion for the newbies who are building a tricopter...try the 1.6 aero version firware
you can download the flash tool from this link...http://www.kkmulticopter.com/index.php?option=com_content&view=article&id=174:kkmulticopter-flash-tool-by-lazyzero&catid=59:software-resources&Itemid=65

I bought one of these and reflashed it with KK Twincopter V 2.5. Then I connected both the motors and also connected the throttle channel on the board to the receiver's throttle channel but no matter what I try with the sticks and the trims, I am unable to get the board to arm. Should I try flashing it with a different version or is it necessary to connect the servos and all the other channels on the board to the receiver?

YES IT IS NECESSARY !!
only throttle channel connected to rx won't arm your board. If you have throttle on left side you should have channel 3 and 4 connected to the board.better connect all channels. PROBLEM MUST BE FIXED.

You will definitely need throttle and rudder channels for arming it, FWIK.  Not sure if it insists on all 4 channels being connected.

Yes as anwar bro said
board detects two position to be armed.
1. throttle stick to zero
2. throttle stick to left(if you have reversed channel) or right.
If there's only throttle channel connected to board, it will detect only zero position.

Thanks, will try that and update as soon as possible. I actually had to modify the servo extensions so as to connect the receiver to the board(because I never knew one needs those before I actually got the board). Now I have 3 servo extensions with me and I'll connect all of them to the board(throttle, rudder and either elevator or aileron). Will update here ASAP. Thanks again.

Alright, I plugged in the rudder and throttle channel and the board did arm. I was also able set the range and got everything working fine. I then plugged in the servos and connected the elevator channel on the board to the receiver but the servos don't work. Maybe I need to plug in the aileron channel as well??

Ok, I plugged in everything, but the servos still don't work. Does the quad board only work for motors? Or is there anything else that has to be done?

What is required is step by step debugging.  Since you are building a TwinCopter, you should have two motors and two servos, right ?

Now you should start asking question to yourself like :

1) Do my motors work when I increase throttle ?

2) What if I connect a motor to a channel on which a servo does not seem to work ?

3) Are there any servo specific configuration in the setup of the board/firmware ?

I assume you have done basic checking like you do not have the servos plugged in reverse etc...

Anwar sir, the motors run fine and the gyro for roll too works fine so I am getting stability in roll. Basic checking has been done. The servos however move a little with throttle input but inputs from other sticks has no effect. I'll try 2, as far as the configuration is considered this is what I am following http://www.kkmulticopter.kr/index.html?modea=vieweng&mc_selected=MultiCopter&sc_selected=KKMulticopter&sn=multicopter_v02_tw&id_no=57
It says motor on 1 and 2 and servos on 3 and 4.

the servos will work with the board..some firmwares are little bit different.sometimes the board works perfectly after lifting the twincopter to a specific height(in some cases).what i mean is lift and roll will work fine,but the servos may work in the flight.so do one thing,try a test flight by securing the flight with tight threads.be careful while testing and make sure you test in open area.all the best