In April of 2018, it was determined that switches SW1 and SW4 pose a safety hazard.

Affected products: All Vernier Circuit Board 2 (VCB2), shipped prior to April 11, 2018 with the mark
     VCB2 REV 1 PPRL 2015
and the mark
     VCB2 REV 1A PPRL 2015

All users of the Vernier Circuit Board 2 with these marks should remove all batteries from the battery holders and stop using the unit immediately.

To identify if your board has the issue, look for the mark below pins 35, 30, and 31:


The affected parts of the board are switches SW1 and SW4:


The issue with switch SW4 is that it is possible to place it between two locations. If batteries are in the battery holders and the switch is in an in-between spot, the batteries can short-circuit and overheat to dangerous levels.

Switch SW1 is also possible to place in an in-between location, which could also cause a dangerous short circuit.

What do you need to do?

  1. Stop using the VCB2 immediately.
  2. Remove all batteries from the battery holders immediately.
  3. Arrange for a retrofit of the circuit board to eliminate this problem by providing your information in our recall form:

We will send you a prepaid UPS label to return the units for a free upgrade.

If you have questions, please contact, or call 888-837-6437.

See also
How do I know if a VCB2 has already been upgraded with new switches?