Hello PB, 300k (or,bk,y,go) is installed at OB to -reg. Resistance reading from -reg to ground is 0.
{The 300k resistor reads 300 @ metersetting 2m.}
Yes 19 and B4 are wired together. Yes 9 is wired to 19/B4.
I will keep inspecting all solder points and connections.
Thanks for your help,
vpeele