I just tried what you said but it didn't resolve the issue. I tried unplugging the TV and pressing and holding the Power button on the TV while the TV was still unplugged and I tried the same process whilst the TV was off but still connected to the power supply.
Tried what you said with the remote, removed the batteries and held the power button, also tried this with the batteries in. Still no luck, the TV is still returning to Channel 1 every time. I am sure that this is because I have programmed the remote to do this by mistake. The remote is model number Hitachi RC 3900 and I am sure it is the original remote. The aerial is a VHF outside aerial on the the roof of the building where I live. And the TV is not connected to any type of Satellite or other type of box.
Do you know how long it will take to get an answer? Or if someone will reply and say that they don't know?
Do you know approximately how long it will take before this problem can be passed to another expert? I think it would be resolved by taking the TV and remote back to factory settings?