Stairmaster 8G Gauntlet Service Manual page 41

3. Test for 12VDC coming from the power supply via
the barrel connection (Fig. 3). One probe should
be inside the barrel connector while the 2nd
probe is touching the outside of the connector
as shown.
4. Test for 12VDC coming from the power inlet
cable into the EMI filter (Fig. 4)
Fig. 3
Fig. 4
Page 41