Strange occurance with power

Toshiba tv. Unsure of model.

My power button stopped working for the tv on sky remote but it controls all other tv function and sky fjnctilns eg volume.

Brought new sky remote but exactly same.

Reprogrammed sky remotes and all same.

So found orignal tv remote and exactly same all functions work except power button.

So 3 remotes all work perfectly well except power on/off function.

Tv will turn on/off usong power button on tv and will switch off if if i set the tv timer

Completely Puzzled