Hi, I have a 1500w inverter, 12v- 220v. I have used it to power all lighting and appliances with no problem except for the computers power supply. Whenever I plug the computer( even if its turned off) all the open lights would flicker on and off and the computer would not power on.No tripping on the inverter.When i removed the plug,all lights are back to normal. When i switch to grid power, computer and everything is working fine. pls help.