AC Green light blinks _before_ connecting to laptop - PA-2

I have old laptop which i wanted to run today and check some things. Earlier it was running without a problem. First I was connecting adapter to power supply and noticed already that light is not steady green, but blinking. Of course pluging it into laptop and powering up was a failure.

I assume that a problem is with a power adapter. However i cant find anywhere any info about this on support. I dont want to buy a new one without knowing it for sure.

I would be glad for any info.

Thanks in advance

Wojciech