Mitsubisi tv CS- 40307 digital capable ?

If the TV is an analog only you will need to get a digital converter box to be able to use a digital antenna. You can find this online by doing a Google search or you can try Ebay they have a bunch of them 662results for tv digital converter box

To use this TV with a digital signal you need a digital to analog converter. Here is a link for a converter and one for the TV user manual.
Hope this helps.
Bob
Samsung CM19033 User Manual

Zinwell ZAT 970A Digital to Analog TV Converter Box for Antenna Use

If this is an older standard tv it is analog only it's not capable of processing digital tv transmissions in any way by itself you will need a digital tv converter box. thats true for antenna reception or cable systems that supply a digital signal,with digital cable systems you will probably need their digital converter box over the air & digital cable converters are not compatable with each other.

not sure what switches your fiddling with but first thing is check your fuses are ok

use your remote then turn off the text messege of your tv.the black screen that you seen is for the messege but since their is no message written in the box ,that's why you see a black box.

try to check the horizontal output transistor if it is good,check up the power regulator

thats problem is only a lose connection,if you know how to used a soldering iron ,solder the vertical section of your tv.

most new tv's are digital capable...
but here is the trick the convertor box are only for those who don't have cable or satellite service if you use only an antenna to get channels then yes you will need a converter box for each tv that uses only the antenna to get channels if you have satellite or cable service then they don't need a converter box even if they have basic cable they won't need the box there channels are already digital converting now there are a few events that was in anlog but there are being converted as best as possible but you may notice the difference in the pictures betwwen analog (usaully old time movies or show even commercials) Digital (most everything now that are new stuff are digital and even in hd now)...

No this set isn't. I think you'll need a converter box. This is classed as an analog TV.

I hate to tell you but if parts are not available is not a good sign,consider buying a new TV and get it over with.