The switch for the machine that varies the length and temperature will only work forwards. What could be causing this? A faulty switch or control board?

margaret lucas, December 2016

Thanks so much for the quick informative reply. Really appreciate it.

margaret lucas, December 2016

Based on the manual (Here: https://www.manualguru.com/gbc/620os/users-manual/page-7)

There is a master switch (Increase/decrease) and separate3 switches for "length" and "temperature", as well as "Burst".

The fact that the Master Switch only works properly in one direction, on at least two variable functions, suggests either:

* The switch is faulty
* The wiring or a connector between switch and control board is faulty
* The control board is faulty.

Some very basic electrical checks with a multimeter should be enough for a competent technician to work out what the problem is.

XXX, December 2016