Ok,

I'm having trouble now with my latest box, 2nd in 4 years.

When it starts sometimes it takes 5 or more mins on the boot screen and then I get a message Internal HDD cannot be found.

I know its not the hard drive because if I unplug the external version and replug the internal drive, I can still get the same result, so I suspect HDD controller.

Can anyone confirm?

BTW The fault is intermittent and the box can go for weeks ok and then refuse to find the HDD.

If you've eliminated the hard drive itself as the cause then If it's intermittent it sounds like it might be a loose connection or bad solder joint somewhere. The ambient temperature//humidity could mean it just makes contact sometimes and not others.

Do you always have an external hard drive connected?

Also is it USB powered?

Automan.