I usually use my RX2/3 in 2 battery mode. Yesterday, I changed out my batteries as usual, but when I put the fresh set in, it said "Check Battery." Panicking, I tested a number of combinations, deep cleaned all contacts, and finally partially disassembled the mod in an effort to figure it out.
Here is an album of pictures describing my problem.
The mod will not fire at all. I've updated the firmware to 4.12 and 4.13 to no avail.
Upon disassembling, I tried shorting the "battery door" contacts with a large piece of wire, imitating the job of that jumper bar in the two battery back. The mod immediately came to life and worked fine. If I pressed in the top "battery door" contact, however, it again thought that the batteries were dead. As long as the top contact is pressed in at all, the RX2/3 thinks it's in 3 battery mode. I can't figure out how to fix it, and Wismec has of course not replied to me yet.
I found another thread on ECR where the OP appears to be suffering a similar problem, and I've seen more threads before with similar things. They're usually dead ends.
If anyone has an idea I can try, or a link to another thread, please help. I don't have the money to replace this mod right now, and I'm devastated that it's broken. A Reuleaux was always my dream mod, from when I first saw an RX200. The 2/3 is better for me, due to the battery choice.
Anything anyone can do or anyone I can contact?
EDIT: /u/HustlinTomTurkey has the fix! Read it here! He also made a separate thread for this. Here is the link.