Don't you have access to the impeller? With most powerheads I see (Asian brands), you just have to twist the bottom part (nozzle) to about 90 degrees and it comes off then you have access to the impeller. I do what the others do to. I have a 9 yr. old powerhead that won't start after water changes. I just move the impeller several times with my hand and it goes functional again when I plug it.
Not familiar with your brand though. Might check it out. Good luck