sounds to me like the eye is working perfectly. 10 w/ a yellow paintball means it's reading almost 100% and then to 250 w/ breach open means its reading almost nothing and 140 with the bolt is absolutly perfect. the board can now determin the exact phase of the firing cycle by the eye reading.
BTW you can test the eye funtionality with out shooting, just take out the cocking rod and cycle paint and fill the barrel
ok, next check to make sure you have a good seal on the eye itself. if sunlight can get in to the breach it can majorly screw with the eye readings. also set the frame to factory fast. (turn on and push the orange button inside the grip frame to get to the menue) the only other factor that I can really think of would be that broken connection. but if you have repaired it and isolated each wire, it should be fine. A wire grounding to the body can nuke battery life too. sounds like that is handled though.
keep at it, and keep us posted.
good work on the HPA, I have a K tank in my garage! (I feel your pain)