The first steps are followed in What to check before opening

The unit is then opened by Opening a baton.

The unit is checked inside and the relevant component is repaired as per the components from Hardwrae guide

If no fault is found but the customer insists there is a fault follow the Intermittent fault guide to do some extra tests and hopfully find the fault.

Upgrades can also be identified and carried out.

Closing the baton can then be carried out.

The final step is to carry out the final QC