If you have totally irrefutable proof in the pics that you have alluded to that the item was working and IS as decsribed then you can try presenting that evidence to ebay for their consideration. But don't hold your breath while you do it tho.

Don't rely on emails, you need to speak with them. And use the callback feature, you seem to get a better quality CSR when you do that.

INAD is pretty difficult to argue with as ebay will notoriously side with the buyer whatever they say.

This is the monster ebay have created these days, so if the business model does not suit you then I'm afraid you will need to look at other selling platforms. Personally I believe its a very dificult place to sell high value items these days, especially electrical/electronics items. You are very likely to lose your item and your money too. Much less heartache to simply throw it in the bin really.