Have TV Questions? Ask a TV Technician
Hi Tabitha and welcome to JustAnswer,Thank you for the question and your patience. With the indulgence of Rick and should you still need assistance for information purposes only...Initially, would the "...makes the noise of turning on and off..." be clicking sounds?
Still, the described symptom almost always point to an internal hardware issue or more particularly, most likely suspect would be the power supply circuit similar to the product offered HERE. Depending on the version/board number, there may be repair kits available for the power supply board such as those shown HERE.
Either of the above repair approach would require that the unit be opened up for visual inspection, voltage/continuity/resistance checks, confirm faults and effect repairs.
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?
Please post back how you would want to approach this and/or should additional information be needed.