"no input device found" on TV screen, need help PLEASE

hello there,

i just inherited a SAMSUNG HPS4253 and tried to set it up in my room last night. I used an old-fasioned antenna cable to contect my comcast with TV in the ANT1 In (cable). I turned on the TV and it said "no input device found" or something to that effect on the screen. I thought I might need a cable box so I grabbed the motorola cable box that came along with comcast. It worked fine on my old school chunck TV. But I still receive the same "no input" message after I conect the cable with TV.

Do I need replace the antenna cable with something else? or is there any other tricks to do the work? I checked the "input" and there was only "TV". "AV1" and other options are all in grey and unavailable.

Any help is greatly appreciated.

What does the TV manual say about using the set's internal tuner? Does the set have a QAM tuner? (That's the cable version of the ATSC tuner needed to receive digital over the air signals.)

If you connect a set top cable box, then you need to attach the STB output to a video input, not to the antenna input, because the box will have already done the tuning and will be outputting video.

As a test, I'd also try using an off-air antenna. Rabbit ears should be fine for test purposes just to see if the TV can tune in an over-the-air digital signal.

You may also need to select which input you're using in the setup menu of the tv.