Line fault at the outlet -- do I need an electrician?


Yesterday, I got a Panamax, Max 1500 surge protector and line conditioner. (I got a very good deal on it, and am just trying it out.)

I plugged it into an outlet I've been using for a while and one of the red lights on the front lit up saying "line fault." (I'm not sure how this is different from a "ground fault." Maybe it's the same.) The Panamax does not do this with other outlets in the room. They seem ok.

So, I know this means that the outlet is improperly wired. My question is, might this be a simple thing to check and/or fix? Any suggestions most appreciated. It's the only outlet I can use to have my audio set up where I usually have it. Now is not an optimal time to call an electrician. If this is a big problem, I'll try out my gear somewhere else in the room, but if I can fix this without too much expertise, that would be ideal.
128x128hilde45
A subpanel is a panel fed from another panel.

Like in my old house I had a 200 A main panel, but a sub panel in my workshop. The physical size isn’t the determining factor. What makes a sub panel a subpanel is that there’s another breaker in the house which controls all power to it.

The 200A main panel (techincally service panel) fed a subpanel via a 60 AMP breaker. That subpanel had 4 other breakers.
If your house has aluminum wiring, (or not?), you should try unscrewing the outlet (with the breaker off), then remove the wires, and tighten them to the screws, not the push in inserts.  To remove inserted wires, push a very skinny screwdriver into the little slot by the wire.  Corrosion can be defeated this way, especially on aluminum wiring.   
... and yes, check the polarity:  White wire goes on the screw for the small plug insert slot.  Do the green (or un-sheathed) ground, too.
Yes, I definitely do not have a subpanel.
Appreciate all the comments.
For me, this is adding up to waiting.
If I change my mind, I'll update.

You're a generous group of people.

I wish you health and as much happiness as possible.
@ hilde45 OP

(If the plug on the power conditioner cord is a molded plug.)

All you need to do is cut the plug off the cord that feeds the power conditioner and install a new plug. You will reverse the Hot and neutral wires of the cord on the new plug’s terminals.
Neutral wire to black color screw on the plug.
Hot wire to the silver color screw on the plug.
Green ground wire to the green screw terminal.


125V 15 amp 5-15P plug.
https://www.homedepot.com/p/Leviton-15-Amp-125-Volt-Industrial-Grade-Straight-Blade-Plug-In-Black-Wh...
.