Thank you for your replies.
I have been able to read the markings on the IC
IC1:
OB2202CPTesting the Pin8 (BO), and Pin6 (VCC) came back with zero volts. with the unit disconnected from the mains I did a continuity test, and found a dead short from GND and VCC. Looking over the PCB some more I found a solder bridge across C2 (10uf 50v) this is across the power rails for the IC, after removing the solder bridge I now have some voltage readings at the IC.
Pin4 (GND) and Pin6 (VCC) = 1.91vdc
Pin4 (GND) and Pin8 (BO) = 1.40vdc
Pin4 (GND) and the output between RX1 and RX2 = 24.5vdc
Looking at the datasheet the min VCC voltage for this IC is 11vdc
I have been trying to draw a Schematic but I can't get my copy of DaveCAD working and I keep on making errors
Looking at the PCB and tracing back from Pin6 (VCC) it seems to be getting power from the output between RX1 and RX2, via R5 a 100k resistor. one side of the resistor is reading 24.5vdc the other side is reading 1.91vdc