Hey guys, I am getting a switch 57 error on my TZ. I pulled the sensor and noticed it had a cracked solder joint at the 7.5k resistor. After fixing that, still not luck. Is this supposed to be open by default? I'm assuming it is which is why it is throwing the error. I am torn between replacing 4N35 and TDA016 or just replacing the whole damn thing for $54.
Anyone have any experience with this? I buzzed out the board and checked the diodes. All those appear to be fine .. I was never any good at checking logic controllers or chips and such 
I also read you can replace the 4N35 with a CNY17-3
The board it in great condition, I'd hate to replace :/
Hermosa Beach, CA
