Hi all - how can I fix when the powerline LED of my extender stays off.

I was trying to add an extra extender earlier today. After several failure of pairing it with my existing extender (the powerline LED turned red each time after the pairing session), I pressed the reset button of the extra one (for about 3-5 seconds). Since then, the powerline LED stayed off. I tried unplug it and put it back to the wall socket - it turned red for the first 1-2 seconds before going off. I tried connecting it with ethernet or through Utility, the powerline LED still stays off. Any tips to resolve the issue?

Thanks.