I have on my mountain bicycle Deore LX for a couple of years. The easy fire is only able to move the derrailler between 5th and 9 th rear cogs. If I try to move the derailler obove the 5th cog, I cannot, the easy fire trigger just moves freely without "grabing the cable". All the rear gear system is well tuned and this malfunction is not related with the limiting bolts at the derrailer or the settings of the cable housing. please guys, help me find a solution to this malfunction.