plays while connected to power but dies when unplugged

my clip has started to only work while plugged in to charger or other mini-usb (but seemingly will not charge it)…I think the battery is dead.

what do people recommend to change battery or is there a hardware thing that can get destroyed to take out battery power ???

If this happened suddenly, and especially if yours is an original Clip, it could be that one of the leads to the battery came undone, as a result of a drop of the player or otherwise–this was a not uncommon issue with the original Clip.  In that case, you could gently pry the Clip open and either resolder the lead back or affix it using conductive epoxy.

I opened it up and the leads seem to be connected (neither were completely detached).   the unit is about 6 months old with infrequent use.  

when it is plugged in the battery bar just is blank (no indication of charge), when it is unplugged from power source it just goes black and will not turn on until plugged in to power source.

Definitely sounds like a battery issue (or related circuitry, if the leads are connected?).  Did the issue happen suddenly, or gradually?

Note that new Clips have a 1-year (2 in the EU) warranty–you could telephone SanDisk for a warranty replacement, if you’re covered.

Can you try a different cable to see if it charges?

does the same thing with different cables and sources (computer, car charger, wall charger).

This just started suddenly.  I will look into replacing the battery and how to do it.  (maybe there is a thread on that here somewhere), not sure if I have a receipt to show for a replacement).

Why not try contacting SanDisk for a warranty replacement before anything else (including possibly voiding your warranty by trying to do a self-repair)?