TE-WB 1.1 & 1.5 Debugging

Common 1v1 & 1.5 Problems

Preset Pots Short Out to PCB

The most common construction problems found on version 1.5 PCBs is one or more of the three preset potentiometers shorting onto traces that run between its legs. The arrow in the image at left shows the sharp projections that can break through the solder mask to cause this short. The image at right shows the PCB traces that are close to the holes for the pot.

The solution is simple - don't force the pots into their holes before you solder, or, if you have already soldered them, simply lever them up, a leg at a time, while applying heat to the solder joint.

Here are some symptoms that are caused by the "pot short out" problem.

The red LED fails to come on, even though the sensor is connected and heated.
The 2.5SET control cannot be made adjust to 2.50 Volts and/or the Vcc is much less than 8.0 Volts.