I have a magnavox mod.mwr20v6 i have a magnavox mod.mwr20v6 dvd/vcr 4-head hi-fi stereo.the

Question

i have a magnavox mod.mwr20v6 dvd/vcr 4-head hi-fi stereo.the problem is when i'm playing a vcr tape,it plays for 16 seconds then shuts off.it does this every time.not sure what year it is.i'm at my mom's house.thanks for any help.