My trusty Logik DAB/FM radio (nothing special, but decent enough sound and perfectly reliable up to now) has suddenly developed a very loud hum. This isn't the "standby hum" that many have mentioned but is across the output: turn the set off and it disappears, turn it on again and it comes back (sometimes after a minute or two depending on how long the radio has been powered down). Does anyone know if this likely to be a repairable fault? Or am I faced with replacing the set? Many thanks, Bert.