Hi and welcome to JustAnswer,Thank you for the question and your patience. Should you still need assistance for information purposes only...Initially, is the Magnavox completely / electrically dead?
As this would almost always be an internal hardware issue, are you then considering a DIY (do-it-yourself) repair approach? If yes, do you have access to and familiar with a multi-meter and even a soldering iron?
If all external factors have been checked and ruled out, then the described symptom - completely / electrically dead always point to an internal hardware issue. More particularly, potential suspects after a review of the Service Manual are:
All of the above would require that the unit be opened up for visual inspection, voltage/continuity/resistance checks, confirm faults and effect repairs.
Please post back how you would want to approach this and/or should additional information be needed.