There are a few possibilities. 1) You have the system on wrong broadcast system. Press the TV.Sys button on the remote. (In the US, you need the NTSC (analog) broadcast for older TVs). If you have lost the original remote, you need a replacement that matches the feature. See http://www.remotes.com/remotes/servlet/rs?a=gmi&uuid=12937326385240&smodel=DVD505&brand_pn=COBY_DVD505
for a substitute remote. 2) You have mismatched cables/inputs.
For the second issue, a composite video cable could be connected to a component video input. If both devices have component video, get a component video cable (red, blue and green for the video, separate red/white cable for audio); it isn't included with the player. Otherwise connect to the composite (AV) connections on the TV (yellow for video, red/white for audio).
If needed, you can reset the player as follows:
****RESET THE DVD PLAYER BACK TO THE DEFAULT SETTING***
1) Open the DVD tray.
2) Press the "Setup" button.
3) On the "Down" arrow, press it three times.
4) On the "Right' arrow, press it once.
5) On the "Down" arrow, press it three times
6) On the "Right" arrow, press it once, then press "Play/Sel" button.
7) Press the Setup button to exit.
*The default setting will take affect as soon as you press the setup button (step 6).
I hope this helps.