Vintage KORG AT-12 Auto Chromatic Tuner Made in Japan FOR PARTS OR NOT WORKING

In great cosmetic pre-owned condition. Does show some signs of wear from use throughout the years such as light scratches and discoloration on the ear piece. Shows some signs of corrosion in the battery compartment, please see photos. The tuner turns on ONLY WHEN USING THE CHARGER, does not turn on when using only the batteries. The ‘UP’ button does not work. The rest of the settings seem to be in working condition. Please see all pictures of this item before purchasing.