blank screen, click wheel still clicks, swapped HDD, Logic board Shot?

The so called "genius" was right, the hdd dies - but you can try something with your iPod - if it works - keep in mind that the hard drive could die within minutes, days or years - nobody knows...

hold the iPod around 4" above and "drop it" - make a hard reset and if you are lucky - it will work again

here is a howto video on youtube

the white screen has nothing to do with the clicking, i would try a hard reset (press and hold the menu and the select button at the same time until the iPod restarts - that should be done within 10 seconds)