I'm not sure how long I've had my Nexus 9 for at this point, but I love it. It's basically an e-reader with good screen resolution - I use it for Mendeley, Kindle, Google Docs, and various sites on Chrome.

About two years ago (I think?) I was having problems with lag, slow loading, turning itself off, etc. and I sent it away to some repair place I found online to have the motherboard replaced. Lately it's been lagging a lot again, although we're not having the spontaneous shutdowns, at least.

Do you think it's still the motherboard? Is it worth having it repaired again? (It was cheaper than buying a new tablet.) Or are the parts for Nexuses too old by this point not to wear out quickly?