My Maxent TV (MX-42HPM20) of 3 years just stopped displaying picture. Even menu doesn't come up. Power light is on, but screen is black. Any thoughts?

I have the exact same model TV that had the exact same problem. It is most likely your YSUS board. With my TV I replaced the YSUS board and the ZSUS boards because I bought them as a set on ebay. After the boards were replaced everything worked like new.

If the television is still getting power, and even more diagnostically important is if you're still getting sound from the device, you've got a back light issue. All LCD TV's work on the premise that your image is displayed using a set of white tube back lights, think similarly to the ones you would have overhead in your kitchen at home. The issue is that if these lights ever burn out, you won't be able to see anything on your TV, like the situation you're in now. You have to get these replaced by a technician. The issue you're going to run into is that Maxent is no longer in business, you'll have to find a service depot in your area that can assist you. The repair is fairly common and shouldn't run you more than about $300-400 at the absolute most.

WRONG!
WRONG!
WRONG!

This model is a plasma not a lcd. So it doesn't have back lights.