For the 8735AD the entire unit has to go. The board has soldered connections. The tech said there is a jumper fix that sometimes works with the old firmware version 1.7. They will update firmware to version 1.9 and "lock" it in LiFePo4 if I ask. Sounds like your experience...carpense said:@rfuss928 Interested in hearing how it goes. It only took me about 10 - 15 minutes to pull out. Reinstalling was about the same amount of time. Good luck!