Finally it is replace with a new inverter. The previous inverter broke down due to excessive electrical overload which causes the casing of fuse to melt and make the inverter non operational. Interestingly, the fuse did not blow.
Next, on 9 May, I went to Hope Village at Prey Veng (East of Cambodia) to replace the old lead acid batteries with new deep cycle lead acid batteries. The batteries were getting old and not getting full charge for the solar. The security lights shut down at about 2am in the morning because of the weak batteries.
I returned home on 11 May 2009.