TV takes hours to turn on
My 42inc LG HDTV 1080 is taking hours to tun on, sometimes it only takes 20 minutes but today I been trying since noon time
Really sounds like a power supply issue, probably the electrolytic capacitors. Once the electrolytic caps in the power supply start to go bad they have all sorts of power issues, from taking along time to turning on, or never turning on or turning off randomly. If you are not familiar with capacitor failure in tv's you can do a lot of research on the internet. It's really not a hard fix if you are patient and handy with a screw driver and soldering iron. Heres a good example of what you would expect to see in the power supply if you took the back off.: https://www.google.com/search?q=bad+capa...
I would replace every single electrolytic capacitor in the power supply. Also if you use higher quality capacitors it will last longer than it did before too.
If you are not comfortable with removing them, you could look into buying a complete power board replacement on ebay or bring it into a repair shop. Hope this helps good luck.
Bad capacitors are extremely common in budget brand or old TVs, but this is not a common symptom of that. Generally once they start going bad, you might get funny behavior for a short while but then the TV completely stops working, not ever coming back not rather than just taking a long time.
What is more likely depends on whether it's being turned on by the remote or a button on the set. On the set the button may be misaligned either from the factory or worsened through the stress of pressing it hard (or poor design subjects it to this) or in the case of the remote, a buildup of tobacco tar on either end, remote or receiver panel, or time of day (sunlight in the room), low remote batteries, etc.
Then again for all we know the problem isn't even the TV. It could be that the source, a CATV tuner or internet connected box, etc, is not on or not receiving signal. Never underestimate people's ability to overlook something the more complex the setup is.