Looking to find out what that component is (again 
)
I drew part of the circuit, it looks like it is a shunt regulator just like the TL431 used in smps feedback loops.
It says DI 48, the middle pin is GND. The supposed reference voltage divider resistors don't have values printed on them. The opto is a TLP181. The voltage to be regulated is 5V, sometimes it is sometimes not, that's the problem.
I attached two pics.
)I drew part of the circuit, it looks like it is a shunt regulator just like the TL431 used in smps feedback loops.
It says DI 48, the middle pin is GND. The supposed reference voltage divider resistors don't have values printed on them. The opto is a TLP181. The voltage to be regulated is 5V, sometimes it is sometimes not, that's the problem.
I attached two pics.
