Facing TV Problems? Ask a TV Technician.
Hi and welcome to the site, I’m Louie. Sorry you had to wait awhile but I’ll do my best to help.
Initially, consider an experiment (if have not been done). Power on the TV and set to a program/channel. If at all possible, darken the room where the TV is. Wait for about 5 minutes or more. Shine a flashlight at an angle (not directly) and nearly but not touching the screen where the volume level / menu display is usually seen.
Press the VOL UP/DOWN or MENU button and note if a dark/ghostly image of the volume level or MENU could be seen.
The above is a test to determine if it is a backlighting issue.
...dark/ghostly image of the "...CBS logo..." ?
Unfortunately, the described symptom almost always would be indicative of an internal hardware issue.
Are you then considering a DIY (do-it-yourself) repair approach? If yes, access to and familiarity with a multi-meter may be needed.
Would information / contact details of an independent TV repair shop serve your need then?
On "...Any way I can get to the menu to check the input source...", there would be a MENU button on the side panel of the TV as well as INPUT button. The challenge would be viewing these as the screen would be dark.
If considering accredited / independent TV repair shops, please click HERE.
Select your state or better yet key in your Zip Code and then click on the Submit button.
I realize that the above information may perhaps be not what was expected. Unfortunately, there is no quick-n-easy fix and neither is there a workaround; sorry for having to be the bearer of bad news.
Could still be.....or likely a cold solder / loose connection with the backlight/inverter circuit.
...or now even the power supply that powers the inverter.