UPS not working!!!
I am facing a big problem with my UPS and I would be very thankful if any of you could provide me with a solution.
I have connected my computer to the main power supply through a UPS. This means that the plugs of the CPU and the monitor are connected in the UPS sockets, and the plug of the UPS is connected with the main power supply. My UPS had not been working since the time that i purchased it. This means, that when the main power supply is on, the computer works perfectly well, but when the mains is switched off the monitor screen goes blank. The green light in the CPU is still there, but the red light doesn't appear. The sound of the SMPS fan is also audible. But the computer doesn't work. I thought that there must be some problem with the UPS. So, I got it replaced by the manufacturer, but still the problem persisted. When I talked to the manufacturer about this, he got the UPS checked at a computer in his shop and the UPS worked perfectly fine there. He suggested that there may be some problem with the internal wiring of the monitor or the CPU. So, i took the monitor and the UPS at a neighbour's house and connected both of them with the neighbour's CPU. The UPS worked perfectly fine with this combination.
I think that this means that there must be some problem with the CPU. What kind of a problem do you guys think it is and what further steps should I take to correct it?