I had the same problem a couple of weeks ago and it was driving me bananas.
It turned out that the positive side of the battery had a loose connection. It looked good at first sight, all squared up, etc…glad I checked anyways.
bought my TKX kit from SST. they give you everything you need. its fairly easy to swap, especially vs a T56, from what I've read at least.
just finishing up the break in process and it is SWEET!