The primary winding of your OT-5 is open. I see this happen from time to time when the lead out wire get accidentally cut during a build. If you look at the base of the solder terminal, the wire coming out of the transformer will be wrapped around it and soldered. If you look on the side where you're having the problem, that thin copper wire will likely be cut and broken. It is possible to wrap what's left around a piece of resistor lead and solder them together, then jumper that back over to terminal 10. If that doesn't work, you'll need to seek out a replacement output transformer from us.
