First, I take it that 'problems' of consciousness only arise if you assume that physical things are what ultimately exist, such that consciousness has to be found a home in that picture (a project that is then problematic).

This is already problematic - for if making a particular assumption generates problems that would not have arisen otherwise, then the sensible thing to do is to give up the assumption, not double-down on it!

But anyway, let's make that assumption and try and figure out exactly how this generates a 'problem of consciousness'.

It seems to me that a lot of what is represented to be problematic isn't at all. For example, that consciousness is strange and that we have unique access to our own conscious states. All kinds of state are strange. Shape is nothing like colour. But that in no way implies that such states cannot be states of one and the same thing. Physical things have shape and colour despite those qualities being nothing remotely like each other. Similarly, no matter how peculiar consciousness may be, and no matter how unlike other physical properties, this is no obstacle in itself to it being a state of a physical thing.

Likewise, pointing out that we can explain a physical object's behaviour without having to posit any conscious states also raises no problem at all. It certainly doesn't imply that concious states can't be among the states a physical thing can have. I can explain how my key unlocks the door without having to posit colour of either - that doesn't raise a problem of colour or imply that colour can't be a property of physical things. Likewise for consciousness then.

That we can easily conceive of physical things lacking conscious states seems to me not to raise any real problem either. At most it seems to show that conscious states are not essential states of a physical thing in the way that shape and size seem to be. But that doesn't (to my mind anyway) imply that physical objects cannot have such states contingently. I don't see why a state of a thing has to be a necessary state of it in order to be a state of it.

So far, so much red herring. What's the real problem then?

The real problem - one that I, at least, can see 'is' a problem - is that you can't get out what you don't put in. For example, you can't make something that has size by combining lots of sizeless things. That's just not going to work. The only way to make a sized thing, is to combine things of size - no size in, no size out.

Similarly then, you aren't going to be able to make a conscious object out of objects that are not already conscious (or at least disposed to be). For that would be alchemy. Call it 'strong emergence' if one wants - but that's just a label for what is in fact something coming from nothing. Thus, as our brains are made out of atoms, then either atoms have consciousness (or are disposed to) or brains simply can't have consciousness.

As our conscious states clearly exist, we must therefore conclude (it seems) that either we are an atom - and that, as such, there are trillions upon trillions of us in our body.....that I am just one atom among a vast citadel of conscious atoms composing my body (which, though coherent, seems farcical), or conscious states are states of something quite different to any physical thing. Of course, drawing that latter conclusion means giving up the starting assumption.....which most contemporary philosophers are not willing to do.....hence 'a hard problem'.