He said he is using a brand new fully charged battery.
Really sounds like a short somewhere.
Sent from my LM-V405 using Tapatalk
I agree, TX. I had a saber that had a similar issue, turned out one of the battery connections had come loose and the wire was grounding out the saber. IIRC I fixed it with a little twist and some electrical tape.
Its a pain, but I'd unwind the tape from around the battery pack and controller cards. Check the connections, check the wires. If everything looks good re-wrap everything carefully and make sure there's no contact. Hopefully there's not a broken wire in the mix, but that can happen, too. I never confirmed it, but I had a bad battery pack in another saber that I think ended up being a broken wire inside the pack, the one that goes up through the pack from the far end. I think it was actually broken inside the insulation, causing intermittent failure.
Another option, if this is a new saber, is to send it in for warranty work. Tracing an electrical fault can be hard and frustrating, so you might want to consider that.