Before handing over any digital device for repairs, make sure to take a few precautions, especially if the hardware or data backed up on it is critical.
Data storage media containing confidential information should be kept within the premises of your trusted supplier. If these storage media are faulty, the supplier should replace them with new ones, without sending the faulty hardware back to the manufacturer. If other components display faults, the supplier should remove data from the storage media before sending the hardware to the manufacturer for repair.
If your supplier is unable to guarantee this level of security, avoid entrusting your machines containing confidential information to them, or make sure you remove data from the devices before arranging for them to be repaired (Draft and enforce a Sectoral policy on Physical and environmental security – Maintenance).