I pod nano switches off on inserting headphone into jack

Hi all,

I have an I pod nano 8gb gen 3

It can be fully charged and switched on and working fine on its own ( without earphones plugged in) . on plugging in any make of earphones or headphones there is a crackle in the headphones and the Ipod switches off immediately ( seems to discharge the battery into the headphones or something ) . It then wont switch on again until plugged into computer

Someone said it could be moisture but this fault occurred 2 or 3 years ago , it has been in a draw since then and now on double checking the problem still persists !

any ideas much appreciated !!!!??

Regards

Tom