Within this site, a user had tuned-up their CG5-GT, the predecessor to the AVX...
http://www.astronomyboy.com/cg5/
They had issues afterwards, too. They ended up resetting the computerised portion of the mount, then all was well.
In addition, the AVX is considered too complicated for the average user to disassemble for tuning. But then, as a skilled DIYer, I would perhaps have a bit more success, depending.
The worms, both RA and DEC, should be fully adjustable, and for accurately meshing with their worm-gears; not too tightly, nor too loosely, just right rather.