We have found a MAC 2000 Profile II (S/N:214014556004) on which the centre yoke M5 Allen bolts had worked loose. One bolt had fallen out and the other two were only finger tight. On closer inspection, there was no Loctite on any of the threads.
We therefore recommend that all MAC2000 fixtures are checked for loose bolts at the centre yoke attachment during their next maintenance check or service. Below photo identifies the bolts concerned.

On older units (Profile and Performance before S/N 4023146001, Wash before S/N 4021786001), the inspection can easily be done by removing one of the Yoke plastic covers, bending down the motor wires with a large flat-head screwdriver, and inspecting the screws at the yoke centre with the help of a flashlight. On products after this serial number (and products that have been retrofitted with the later strengthened parts), you need to disassemble some of the yoke cover metal plates before you can inspect the bolts.

If you find that one or more screws have worked loose, disassemble the yoke base for access to the bolts. Loosen one M5 Allen bolt at a time, and apply Loctite 243 (available on P/N: 37021002 Loctite 243 10 ml) before retightening.