is it a quality thing ?

Which? reckon that modern TVs should last at least five years. They go on to say the if a TV packs up within that time it almost certainly had a manufacturing fault and so should be fixed under the Sale of Goods Act. Remember the Argos Warranty is in ADDITION to your rights under the Sale of Goods Act.

As Mikomi is an Argos Own Brand I would write to Argos, demanding that they put the TV right or you will take them to the Small Claims Court. Tell them that you give them 28 days and then file in the court.

T
December 2008