I took a gamble and ordered a secondhand pair of Comtac 2's. Upon arrival they fired right up and noise amplification/reduction seemed to be working fine except the left ear seemed somewhat "weak". My novice brain thought the batteries may be running low so I changed them out and now the headset will not turn on. Tried several different sets of batteries with no success. Indentations on the battery cover indicates that the cover is coming into contact with the contact tabs on the headphones and potentially causing a disconnect. I've tried to power on without battery covers with no success.

Am I overlooking something obvious, is there some sort of chip reset code using volume buttons, or did these miraculously take a dump 30 minutes after I got them. Any help / insight would be appreciated.