Bad power cable no sound

We’re looking into the connector now.

As far as protecting your amp, no problem.
You can verify that by the fact that you can use the PL-IR without power per the manual on page 9, example #2.

The internal power supply converter has a safety feature that shuts it down if there is a voltage surge or multiple shutdowns. If you leave the supply disconnected for a while (usually 10 minutes), it will come back up on next power up.