Curing 'Melted Belt Gunkification.' The Wollensak 4800 vintage cassette recorder was made in Holland for the 3M Company by the Philips Company, known in the U.S. as Norelco. The Wollensak audio machine is almost identical to the Norelco Carry-Corder 150, made in approx. 1967. The only differences seem to be surface cosmetics. It can be seen in some Wollensak ads from 1967. This vintage cassette machine was bought on E-Bay and arrived DOA (Dead On Arrival). Inspection of the cassette recorder revealed the cause of death as 'Melted Belt Gunkification'. This technological disease is sometimes called 'Ampex Syndrome' and 'Teac's Complaint' because it is the same on all these machines. The belts are not made of rubber, but a petroleum distillate mixture that breaks down over time, especially if the machine is stored and not used. The result is the belt literally melts into a type of 'gunk', a gooey, sticky tar like substance that gets all over the inside of the machine. In spite of this slow degenerative technological disease, vintage audio machines that have died can be reborn when the 'gunk' is cleaned out using simple ammonia based household window cleaning fluid (which dissolves the gooey mess) and the belts are then replaced (with rubber this time, please!) Fortunately, the Wollensak 4800 vintage cassette recorder had no damage to its amplifier or motor control circuit, so it was easy to bring it back to life. This video shows how.