dvd player working, and then not working, then working

dvd player,l 5 years old in august, worked fine
then I took out a dvd and put in movie1 and it wouldnt work
I dont get it, it worked later on dvd2 and later on dvd1, but then when netfix sent me dvd3, it wouldnt work

do i need to clean it?
how do I do that?
its not blue ray, and the dvds arent blue ray
my friend told me his blue-ray player that he had to burn codes from the net to a dvd and then insert into the player to get it to work

I have no clue what to do, I am barely figuring out how to post this
Toshiba SD-V394 DVD Player / VCR Combo

thats the player

 

I would try a DVD/CD player cleaning disc (about $10 at Wal-Mart, Best Buy, Radio Shack, CVS, etc.). Since the player is 5 years old, dust may have built up on the lens.

Hope this helps.

 

thanks
my HMDI cord that runs netflix off my computer was plugged in. that seems to be the issue

I dont know why
I had the imput on DVD not the HDMI imput?