Even when the DVD is in the tray correctly, it says "No Disc"

I do not have a blue ray player!! I have a zeki 10inch tablet!! I want to watch my Netflix on it! It was working last night!! Please help me resolve this problem!!

if you have another TV just connect the antenna or cable tv provider cable and see the ur connection is ok or not then you can get the idea

Open the cd tray, blow hard inside about three times. Or get a can of compressed air called air duster and blow that in there.
A third option is to remove the cover and clean the glass laser eye lens with rubbing alcohol and a cotton swab.

If cleaning doesn't help (which usually does) Then the laser circuit is faulty and will have to be replaced.

it seems the lens is bad

HELLO

This is a motor problem. Here is what to do to put it right.

Open the disc tray and switch off the power, then remove the lid off the player. Locate the disc motor and where the spindle goes through the motor put a little WD40 or light oil (but not too much) or it will get messy.

Turn the disc motor a few times yourself and let the lubricant soak in. Leave it for about 30 minutes then try it again - and it should work.

This works in a number of cases, though I can't guarantee it will work for you. TRY IT! (:-)

check to see if you switched to dvd or aux or 1 of the other settings

Sometimes when you unplug the set ffrom the wall power or a while 1-2 minutes, and then plug it back in the problem will resolve itself. The DVD may eject. If it does, check it for damage, warping or dirt. If this does not fix it- you probably should take it to a repair center.

In short, you can. I did it last night. My Bose 321 DVD player is junk and it's always been junk, but I love the sound sytem. Last night, after the thing gobbled it's last DVD, I went through the whole, unplug, wait 5 minutes, plug back in, etc. and it still wouldn't eject so I ripped the DVD tray out of the thing with a pair of pliers, recovered my DVD, and slammed the tray back in, stripping all the gears and screwing up the motor in the process.
BUT, I disconnected the video cable from my Bose and plugged it into the video out on my el-cheapo Tru-Tech $99 DVD recorder. Then I ran the audio out cables from the Tru-Tech to the Aux 1 inputs on my Bose 321.
When I want to watch a DVD now, I put the DVD in my Tru-Tech, turn on the Bose, switch it to Aux 1, and I get a great picture and the Bose sound. Best of all, I don't have to plug and unplug that sorry Bose system everytime the wind blows.
They used the absolute cheapest DVD player they could get their hands on--a Toshiba model--for all the Bose 321 older models. Every single person who bought one has had these same troubles and they've made no offer to fix them.
This was my first and last Bose because of that and I hope more people stay away from Bose until they get their act together and protect their customers. $1000 for a system that eats DVDs like M&M's is ridiculous.

check the menu and see it it hase the same issue if sone one of the main boards are bad.