Observe that the power cord is firmly in place at the machine’s rear panel and at the power source.
I’ve found the power supply capacitors in the USA/Canada DMR-ES30V to be long-lasting. One of my two DMR-ES30V models has more than 4,300 recording hours, the other just about 3,000 recording hours. The DMR-ES30V power supply has two large matching electrolytic capacitors. Unlike some other Panasonics I’ve yet to find the need to replace capacitors in these DMR-ES30V machines.
That does not mean that failing power supply capacitor(s) are not causing the problem. Since the DMR-ES30V power supply is located on its own platform to the rear, capacitor replacement does not require an extensive teardown of the machine.
There may be other problems, sometimes related to the “Digital IF Circuit Board,” the part that carries the machine’s CPU and RAM. That circuit board is not user-servicable, and, if found bad, requires replacement. If a new replacement Digital IF Circuit Board may be found it may be priced at twice the cost of a new (current) machine. Occasionally inexpensive parts machines may be found but one always takes a chance with a machine of unknown history/condition. The Digital IF Circuit Board must be from the very same model so I doubt that a board from a USA/Canada DMR-ES30V would be functional in a UK DMR-ES30VEB.