Heater supply problem?

[was ist los?]

Well i finally built Frank's 12BH7A preamp. I built it in two cases and connect the PSU to the preamp with an umbilical cord. With no load, both heaters power to ~12.10V. However, when actually connected, one heater supply properly delivers the power and the other produces 0V. I measured if there were shorts in the umbilical cord and there were none. Also measured connectivty and everything matches up. Any suggestions?

 

[analog_sa]

Your statements are contradictory and impossible. If you spend 5 more minutes looking at your wiring you'll probably spot the error. Alternatively you can post a picture and someone else can spot it for you.

 

[Sheldon]

A solder joint (or component) that measures fine under no load, but creates an open circuit with load (heat)? Measure voltage at each point along the circuits under load. If one works and one doesn't, the failure spot should be obvious.

Sheldon