Power light not on

@abhijitsoman you are really not giving us much to work with. I would expect that you would tell us at least how you connect it and what you have already checked. When your Matrox TripleHead2Go has no power light, it simply isn't getting the 5V power it needs to turn on. Start by making sure that the USB cable is plugged directly into a main port on your computer and not in an unpowered hub or monitor pass-through. If it still won't light up, swap out the USB cable for a known good one. Also, try plugging the adapter directly into a standard 5V smartphone wall charger, if it lights up there, your computer's USB port is the issue. If your adapter uses an external power supply, you will need to check that as well. Give it a try and tell us what you find out in detail.

Of course, you may also have to disassemble the adapter to check if there are any failed components on the inside. We won't know that until you've checked the basics.