Help with stealth bomber battery/charging issue

Hi,

I have a stealth bomber which won't charge or power up in anyway. The battery measures 71.5v, but when I plug the charger in it drops to 24v. I had this problem a year or so ago and replaced the charger which fixed it. This time I sent the charger for repair and the guy who repaired it said it had a failed capacitor. He has replaced this and tested it to 6amps and says its working, but still no charge.

Not sure how to diagnose if it is the battery/bms/charger. Any help would be appreciated.

When I disconnect/reconnect the battery, I don't get any kind of spark from the connectors like I would expect.

Curious how this was resolved. I thought I had the same issue, but after a couple of hours of charging the charger stopped and the battery indicator jumped to 100%, as it should.