Was it working recently? If so it could be that the adapter blew. If you just pulled it out of storage, couldn’t find the adapter, and tried a random one, that’s probably the problem. Model 1 takes a 9V DC adapter with reverse polarity from most other things (positive outside, negative inside), and if you use the wrong polarity or voltage it’s not going to work (and you could break the console).
Other than that I don’t what could be the problem, I have some power issues with mine as well, that’s what I came on here for lol.