I've problem with my right click razor diamondback 3g, i've to press very hard to make it work,i have bought a mouse razer diamondback 3g 2 years ago my right click it so different with my left click, i'm not sure maybe because i use to play dota a lot. please help me,,thanks

You could try

operatingguides.com

if you need a user manual
or

servicemanuals.co.uk

if you want the schematics etc

We've used them in the past and found them very good.

Also if it is not listed then ask via the link and they
will probably be able to get it for you.

yes, the parts quality of mouse, is now apreciated. Maybe is low quality China Model, dont expect much. So my experience, recomends Microsoft Mouses and Keyboards, It´s more expensive, or less design, but works all days, year after year, is good hardware, no question

its either the contact for buttons and mouse have worn, or the wiring into mouse has became damaged try holding the wire sharply one way to see if it makes differnce, really aint much you can do here other than find is it break in wire or is it contact s to buttons damaged.

Remove it and plug it back to you pc it has not install properly

dear,

yes, u need internal cleaning. So, see the ball side of the mouse and there the arrows or some sign willl show you how to move in rotation to clean it...mostly it is anticlockwise.. 
open it and then put the ball out..clean the ball too.
When u clean the ball then see inside the ball area and you will find the two nos. of roller inside. one is responsible for horizental movement and the 2nd one is for vertical movement. the will probably have dust rapped around them.. clean it carefully because if you push hard it will be the result of broken clips that hold them.
if you can remove the screw backside will allow you perfect cleaning but keep in mind there are two connecting clips infront of the click buttons that hold the front part of mouse...
do it carefully,
goodluck...

hope it will fix the issue so dont forget to rate it...

Your best bet is to probably reinstall the Razor Diamondback drivers.

You can access the latest drivers from here:
http://www.razersupport.com/index.php?_m=downloads&_a=view&parentcategoryid=2&pcid=0&nav=0

Be sure to install the correct drivers for your operating system.

/davey

can't say if your issue is exactly the same as the one i had but my razer diamondback kept cutting out just like how you said, i fixed it by taking it apart and replacing the cable with one from an old dell optical mouse i had knocking around. inside the mouse is a small plastic plug with 5 wires attatched i had to rearrange the wires going into the plug by removing the spades and swapping them around so they matched the original plug.

i found the best way to remove the spades is to get a fine pin or needle and lift the little bit of plastic holding them in, if you do this right they will slide out effortlessly, make sure when you rearange the wires that they're put in the same way as the cable you are replacing else it may not work properly.

put the mouse back together and plug in and it should be fine, it took me 10 mins to do this to my diamondback and its working like new again.

I would check to see if, in your bios settings, that Legacy USB mouse detection is enabled.. That is usually a cause for this problem if it is not enabled....

Also, make sure the drivers you are using are for the right Operating System (ie, Vista, XP Home, XP Pro, etc...)...

under the big plastic slide of the mouse theres a screw you just need to take out .. then gently pop it open the bottom end and pull it back.. DON"T TRY TO PULL IT OPEN COMPLETELY.. there is a little hinge that holds the top 2 buttons in place. just pry open the lower end and gently pull back.