Flux conductivity (NC-559-AS)

[exe]

I was once tasked with troubleshooting a board because a certain regulator was outputting zero volts.

Ouch:( I suspect enable/disable pin was pulled by the flux's conductance to one of rails. I've read a story here on the forum when an oscilloscope had an offset that was impossible to zero out. The culprit was flux under the input buffer IC.