|"Do you think it is possible that the HD video converter box needs a 5V 1A to work in the UK instead of a 5V 2A"|
No, the device is only going to draw as much current as it needs. You could use a 5 volt 200 amp power supply and it would work. The voltage will need to be the same.
"trying different voltages on a multi adapter it did not work either"
That was a bad idea. If you supplied a voltage higher than 5 volts you could have damaged the device.
Send it back, it has been damaged beyond repair. And don't use a travel adapter, it's most likely the adapter did the damage. Current coming out of the wall socket is AC current in the form of a sine wave. It alternates at 50 hertz in Europe. A sine wave is very smooth when it alternates from positive to negative. Cheap travel adapters use triacs to switch between positive and negative voltages and this produces a square wave. Transformers such as the one on the 5 volt adapter do not handle square waves well. It will produce a much higher voltage on the secondary side of the transformer. That secondary voltage is fed into a voltage regulator to even it out at 5 volts and it's probably the voltage regulation device that popped, also taking the video device with it.
When you get your new device, only use the new converter you bought for the 240 volt. And make sure the voltage and polarity are set correctly.