The power button problem sounds like a hardware fault with the power button and/or the ribbon it's connected to, and from a quick google it seems that power button issues are somewhat common with this model. Is it possible that any water/liquid penetrated the external case (the symptoms you report could happen if any of the switch contacts are randomly shorting this could happen, and water ingress could be one possible cause). There are some "self repair" videos on youtube (just search for "desire z self repair"), but they are not particularly easy.. e.g. http://www.youtube.com/watch?v=6UtNU8n0M... Not sure what you meant by 'I can only hear caller through the loudspeaker' - that doesn't sound like a headphone problem at all (if headphone was plugged in, you would NOT hear the caller through the loudspeaker).

I recently experienced exactly this, with my Desire Z, although I wasn't able to exactly solve it. My suspicion was one of three things: a bug in the HTC android rom, a bug in the stock Music app, or a stuck power button. You didn't say if you were using the original HTC rom or whether you'd upgraded. I actually upgraded my rom as an attempt to rule out the first of those (I followed an upgrade guide on xda-developers.com and upgraded to one of the unofficial Jelly Bean 4.2 roms), and I am happy to say that my phone no longer randomly reboots. But I can't identify the original problem because (1) my new rom is not a Sense rom and doesn't actually have the same Music app as the stock HTC Desire Z , so maybe actually it was a bug in the Music app after all, and (2) my power button is definitely stuck and causing all sorts of other problems. But at least not rebooting any more!

You may have a loose harddrive connector inside your iPod. Have you attempted any repairs on your iPod? If so the connector might be loose; if not, it might be that your harddrive has died and needs replacing.

What model of replacement hard drive did you get? Not all hard drives are compatible with all models of iPods. http://www.rapidrepair.com/phpbb/viewtop...

You may have a drive that is *INCOMPATIBLE* with the iPod video 5th generation. The 80GB drive "MK8010GAH", that is usually found in an iPod video "5.5" generation, is actually not compatible with the logic board in the 5th generation iPod video (neither the 60GB nor the 30GB models). This table might help you locate a compatible hard drive for your iPod. http://www.rapidrepair.com/phpbb/viewtop... I had exactly the same issue, when I replaced my 60GB drive with an alternative and discovered this drive was not compatible with the iPod 5th generation. I got the same 'restore in itunes' loop over and over. Essentially, the iPod firmware cannot write to the hard drive, so the restore doesn't work.