I managed to fix my screwed up Xecuter 2 Lite flash and bad Xbox 1.0 TSOP flash.
Fixing the X2Lite was easy. I actually read about it here, but unfortunately I can't find the thread to give credit. It requires another good X2Lite. Just boot Evox with the good X2Lite, swap with the bad, and flash.
As for fixing the TSOP, as far as I can tell, there's no difference in procedure between flashing a good TSOP and a bad one. Most of this info was derived from the thread on using a Cheapmod to flash the TSOP.
1. Flash the X2Lite with the EvoX_MatriX_TSOP_Flash.bin BIOS. I used the BIOS manager to make a 1MB BIOS with 4 copies, one in each location, because I didn't want to do the research to figure out which one would boot and figured I could just reflash it using my other X2Lite. I suppose you could flash it with EvoX_MatriX_TSOP_Flash.bin and Xecuter 4973 in a manner that would allow you to switch between them with the jumper if you don't have another X2Lite to use to reflash. If you don't, you'll have an X2Lite only good for flashing Xbox 1.0 TSOPs.
2. Make an EvoX boot disc with the BIOS you want to flash to the TSOP.
3. Solder the two sets of points that enable writing to the TSOP
4. Ground A15 in a manner that will allow you to remove the grounding while the Xbox is on.
5. Turn on the Xbox, and pull off the middle jumper (disable X2Lite) about a half second after turning on the Xbox. I found the amount of time it takes to push the power button and move your hand to pull the jumper at "normal" speed without rushing is perfect.
6. Xbox should boot EvoX
7. Unground A15
8. Flash TSOP.
The first time I tried this, I forgot to unground A15 and I didn't have an X2Lite to boot the original BIOS. Thus, I was screwed because I couldn't boot from the TSOP or using the X2Lite. I acquired another X2Lite, fixed the original X2Lite, and reflashed the TSOP, remembering to unground A15 this time, and now all is back to normal.
Now I'm having trouble using switches. I arranged my TSOP BIOS flash as
Original 3944 + Original 3944 + Original 3944 + Xecuter 4073
I've tried grounding A18 and A19 (but both not at the same time) but it will still always boot the Xecuter BIOS. Since banks 1-3 are all the original BIOS, grounding either A18 or A19 should boot the original, but it doesn't work that way. Anyone have any ideas why this would be? I removed the TSOP write enabling joins. Does switching between BIOSes in the TSOP require they still be joined?