When you get the svt check car serial address 34-1 for the CCB01
Input is the button output is the tell tale light . On SVT go 1 (ocss) 2 (test) 1 ( RSL I/O ) then it differs on vintage I believe but it may say c equals 1 h equals 2 g equals 3 . If so press 1 . Type in 34 press blue and enter , it will show input output state for 34 bit 1 which is 1st floor button and light . ( if u want to check floor 2 press blue and up to change the bit to 2 again to 3 etc etc ) check the output is OFF if no call registered . If on when no call is registered try turning it off from the SVT press blue and zero until it changes to off then go and see if it extinguished. For some reason on the one in looking at right now if you activate the button while looking at input output state then you HAVE to turn it back off from the tool . Pretty sure thats the case for all. Try this and let us know . Hope it helps .