I have that 6237A 3v0 found it. It's badly copied and most of the components don't match. But, it may have led me to find a Silicon Controlled Rectifier that looks leaky. There is a difference in the diode Check with an exact duplicate of that Rectifier; I pulled them both from the board. One measures .026 both way's which is my suspect and the other is .099. However, they could both be bad. That's why I want the original Manual.