My pv6 mixers red clip lights remain on

FIRST check that your power adapter is 16 VAC at 1 AMP and that it is the original unit.

The clip lights monitor levels at several points. If you cranked the EQ's for maximum, say bass, that MAY cause them to illuminate.

As a test, set all EQ's at mid point. Remove ALL input cables. Are the lights still on?

It is possible that you can have a ground loop that is putting signals in that causes clipping. Another source is if you have a microphone that may be FEEDBACKING at supersonic frequency that you can't hear... that is why we disconnect all the inputs as a test.

Finding schematics so one can repair these devices can be a problem. If ALL the clip lights ar on, then it is probably the reference level source for the clip level threshold... however finding a schematic would be necessary and while part cost would be probably under a dollar, the labor and time to find the schematic would be unknown.