Hello Eileen, I`m Jack a TV repairman
This tv is some 8 years old and it is about that time where it would need some service i`m afraid .
Its been pretty good this far but your tv`s power board now has weak/vented capacitors that need warm-up if you will before they get fully charged and i`m sure that once the tv has warmed up you can turn it off and on again normally .
What you have now are the first advanced warnings of failure , eventually (few weeks) it won`t turn on any longer .
Repairing or replacing that board would fix that and if you or a friend is handy with a scewdriver then this can be repaired at home .
The power board for this tv is not very expensive at around $40 but if this is not your cup of tea then a repair shop may charge somewhere around $120 if you take it to them , they will repair that board .
If you decide to go for the DIY approach let me know and i will help you along with parts and where to find them .
Hope this help and please do not forget to rate by clicking on the star icons at the top, then click on Submit so i get paid for my time helping you .
Also note that it will not close this post , you can come back here at any time if you have questions.