Not sure what the problem is...I turned on my computer & it sounded like it was starting up normally (no beeps; prior to Windows startup). The monitor however only displayed the error message "vga--no input signal". I turned off everything, made sure there were no disconnected wires, & unplugged the computer & monitor from the unlimited power supply (ups). Replugged everything together & straight to wall outlet (not ups) & when I turned on the computer again, it seemed to work & Windows came on. Then after about 4 minutes, my cursor froze/optical mouse wasn't responding (light was off the mouse) & keyboard lights were all off & keyboard not working. I tested the computer with a different monitor, & it seemed to work. I wasn't sure if the probem was the first monitor, so I reattached the computer to the first monitor & all was working well. Then, when I shutdown the computer altogether, the three lights on the keyboard (top right) flickered about 10 times then steady green lights remained on. Also, the light on my optical mouse always stays lit & has always been that way (is this normal?).

So my question is, what do you think is faulty...the ups, the monitor, or something else? How can I find out what the problem is & how can it be fixed?

Your help is much appreciated!

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When you tried the second monitor and it worked, was that with the UPS?

I'd stick with the other monitor and see whether the problem happens on that one after a while. It doesn't seem quite right that it's all going wrong with a monitor so it would be good to rule that out.

Another thing to check would be whether there's any damage to the VGA cable between the screen and the PC. A shorting cable could cause some small problems and could explain why the first screen was the only one with problems (this is assuming you changed VGA cables when you changed screens!).

Let us know!

Thanks, sourcez!

When I tried the 2nd monitor and it worked, it was without the UPS.

I did use the cable attached already to the 2nd monitor when I tested the computer with the 2nd monitor, so I will see if I can try the 2nd monitor with the original cable, in case that is what's faulty. ...will keep y'all posted.

OK, I can't switch out the cable from my monitor to the computer since it's built-in to the back of the monitor. The monitor, keyboard & mouse seem to be working properly now that I eliminated the ups & instead everything is plugged directly into the wall.

My concern is still this now: the three lights on my keyboard (num lock, caps lock, scroll lock) blink on & off about 10-15 times when I shut down my computer and then they remain lit the entire time my computer is off....ditto for the light on my optical mouse. Why is this happening & should I be concerned??

How are they connected to the computer? Is it PS2 or USB? Is it directly or through a USB hub etc?

If you turn off the power at the wall and wait for the lights to go out; then switch the power back on without powering the pc back up. Do the lights come back on?

Just want to clarify your setup first. :)

The monitor & keyboard are both connected directly to the back of the computer. I think that's what you're asking. There's no other box or contraption between the peripherals & the computer. I don't know exactly what PS2 or USB mean.

my computer keep on display no VGA: input signal. What should I do?

If you have a spare monitor test it out to see whether it is the problem if yes you have to replace it. If no, that means the problems like with the computer. Is it under warranty, if no you might have to remove the case and try some simple repair steps yourself.

1) Reseat the ram sticks
2) Motherboard may be faulty or its battery
3)Take a look at the capacitors on the motherboard and see whether they are bloated. They look like small battery

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