Hi and welcome to JustAnswer,
Thank you for the question and your patience. Should you still need assistance for information purposes only...Initially, have you tried unplugging for an extended period of time? ...and then disconnecting all speaker/wires before trying again?
Then it would be indicative of an internal hardware issue as the Panasonic SA-PT950 is kicking in auto-protect mode.
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?
Equally important, could you make use of the repair/Service Manual or at the very least, the schematic diagrams?
Would that be the User's Manual or the Service Manual please?
I'm located in another region hence phone calls would not be practical.
Would you perhaps prefer a second opinion / alternate approach to your concern. I can opt out to re-open this to the other members of the site.