I have a Litecoin wallet that I pulled from the computer I mined on 4 years (the litecoin.dat file is dated 1/23/2014). I had looked at it briefly on that computer and there were transactions showing approximately 121 litecoin but the balance was 0.
I moved everything to a newer, more stable, computer and now I see nothing in transactions at all.
I did use a gui wallet tool to open it and find the keys (about 100 of them) but they will not import into anything I can find.
EDIT: I am really thinking about hiring a service at this point to recover them since the value is pretty significant to my family as I have been out of work for quite a while.