Vintage ROBOTANK Z (battery operated)

This robotank is in good physical condition, It was setting in a box for many years untouched, I unpacked it put in a fresh set of batteries, it ran for a little longer than 5 minutes, All the lights and everything worked. long enough for me to take a video. I turned it off, and then back on and it did not run. I could hear the motor running and it sounded like a gear was slipping. so at this time it does not operate. Sold as is, not working.