You may, if you haven't tried already, need to press the button several times to reset the OS (overspeed) switch.
SOS are automatically reset once the car is moved UP.
Unintended Movement/Ascending Car Overspeed can be reset by pressing the "Manual Reset" in the ITP & then cycling the power. EIP1-3 to EIP1-4 will jump your SOS. EIP1-20 to EIP1-4 will jump Front Gate Switch, interlocks and SOS.
Not sure what GTC is? Didn't see it in my safety chain print.
Is that Governor Tension Contact?
