"このテレビの直し方わかりますか。" means "Do you know how to fix this TV?" but I can't figure out the purpose of の (after テレビ) in this sentence.
直し方 is a noun meaning "way to fix", or "method of fixing".
The usage of の here is possessive:
Bof (or belonging to)
So the translation works as follows:
この | テレビ | の | 直し方 | わかります | か
This | TV | 's | way to fix | (you) know | ?
It is the most common usage of -no: genitive. It connects the two noun phrases: 1) kono terebi and 2) naosikata. Yes, naosikata is a noun, not a verb which I suspect is your confusion.