I own a lightly used Inspiron E1505 laptop which uses a Model # LA90PSO-00 AS adapter.  The AC adapter when plugged in "chirps" and the green light no longer lights when plugged in.  Is this a clean cut case of the power adapter at fault and requiring relacement?  Or is there a high likelihood the laptop hardware requires repair as mentioned in other posts?  I would have expected the power adapter to outlive the useful life of this laptop - given other comments this does appear to be an engineering failure.

Thanks for your help.