[Vectamart]

Gentlemen - many thanks for the responses thus far. The model number that I quoted is per the label on the back of the set. I must confess that all my own searches for the chassis type drew a blank and when I 'Googled' the model number, that also drew a blank so I dragged the set right out and re-checked and the writing on the label is slightly smudged. I have come to the conclusion that the model number may actually be 28PT6773/05R. The set is very heavy and not easy to manhandle so I thought I would try and glean some idea of the likely cause of the problem before delving in.