Hi and welcome to JustAnswer,Thank you for the question and your patience. Should you still need assistance for information purposes only...Initially, the described symptom almost always point to an internal hardware issue. The above would require that the unit be opened up for repairs.
If comfortably able and feel safe to do so, 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 perhaps a soldering iron?
Equally important, could you make use of the repair/Service Manual?