Sometimes your equipment will go faulty within the guarantee period and the seller would require a report to see if it is a manufacturer issue or something else.
Also, if you accidentaly damage your equipment and you have insurance that covers this, the insurance company can require an egineers report for this to see if a repair or replacement is viable.
Tellyfix engineers can supply these reports at very reasonable rate of just £60 (Which you can sometimes reclaim from your insurer).
Just drop off the faulty equipment with your details and leave the rest to us.