Dvd/vcr combo,vcr is fine ,but dvd no picture,or sound,disc reads.

The vcr part of the combo works just fine,no problems there. The dvd part however is not.Whenever I put in a dvd,the disc reads ,but screen remains black,no sound,no picture.When I switch back to vcr,screen is blue,and vcr feature works fine. I no longer get the Apex logo or screen when I switch to dvd.Just black screen. This just happened one day,with no warning. Also, there is a small red symbol in right corner of player screen,only appears when dvd is trying to be used. I have tried switching channels,video1,video2, and even tried switching from regular cable wire that attatches to back of tv,to red/yellow/white cords that plug in front of tv.So, the movie is playing,but no sound/picture. Also,just something I tried,when I push record,I can hear a brief snippet of the sound.Then goes black again,and all is quiet.I have had this machine for about 1 year,and I got it from a pawn shop.This is the first time ever having problem. I just bought some new dvds,and now I cant watch them! I would be ever so grateful to anyone who can offer solution or suggestion! Thank you