Re: Remote mystery
I can't say why it would be an alternate days fault (might it just seem that way?) but remote controls do wear and also get dirty inside.
At a time when the TV
isn't responding, beam the remote control at a digital camera lens and press the buttons in question. If you see the beam flashing away in the camera viewer, the problem is likely with the TV. If you don't see the remote control beam, think about getting another remote control. They aren't usually very expensive. If the handset is faulty and you fancy having a go at mending it.....
Beneath the button you press, is a conductive rubber pad that bridges out contacts on a printed circuit board. After a long time, those pads can lose their conductive properties. Sometimes taking the remote control apart, removing the button and pad assembly (all one bit) from the body of the RC and washing it can work. Quite often, it is found that liquid has found its way in somehow or other.
Having washed and dried the pads (hairdryer works good), put meter leads either side of individual pads to see if they give a good low resistance reading. Compare the resistance reading of known good buttons to the ones that give trouble. If you haven't got a meter that measures conductivity/resistance, put the remote control back together and hope for the best.
Edit: I note you have cleaned inside but the above is the way I always did it.