I have a SW-201 sub that has probably a broken solder connection on the input jack, as I have to jiggle the cable sometimes when the sub cuts out.

I removed the screws on the back (the ones with the arrow symbol next to them) but it seems the back is glued on.

Is this the case, being glued on and not really intended for me to remove the back?

Is there a way to safely remove the back and repair the problem?

Many thanks!