Question [Q] Mtech Fusion low signal problem

I have a Mtech Fusion Mobile.I am using BSNL sim.
I bought this device on april 1st.
At first i was getting good signal reception even in side my house i was getting good signal no drops.
But after April 29 signal begin to drop and it become worse day by day.
Please tell me a method to find did this problem caused by phone hardware ?
if any one else have mtech fusion please comment on this