Chosen Solution

Device stops playing for second approx. and then continue. I checked the HDD in service mode - no reallocks and pending sectors were found. Is the damaged headphone jack could be the reason? I checked the hold button also - it’s OK too. Actually i’m using my ipod with portamp thru line-out, so this is why i haven’t replaced dead jack with new one.

I don’t think you are quite there yet, no reason to replace it already:) Try to format your drive and reinstall your music. The other thing that you do want to do is to repair your jack. The part is relatively inexpensive, that way you know that it is not related to your issue. The iDevice are a bit finicky when it comes to ribbon cables and feedback :-)