Purpose: This document describes debug steps to be performed prior to applying DC power to the fixture.

Pre-PowerUp Steps:

1. Procure a DMM and set it to measure ohms or to the diode check setting.
2. Remove the DUT board clamp from the top of the fixture.
3. Check the orientation of any modules inserted into the carrier sockets. Make sure that the pins are not offset to the socket or that they are not bent.
4. Measure the resistance between the carrier board ground and the ground of all modules inserted into the carrier board sockets. Module grounds are marked as square pads along the edge of the module.
5. Measure the resistance of the two adjacent pins to the center ground pins of the module. If any of these adjacent pins are grounded, the module is inserted backwards into the socket. Another way to ensure proper orientation, is to note that the I.D. tag of the module should be adjacent to the socket markings. Reorient any modules that are inserted improperly.
6. Measure the resistance between ground and all pogo pins known not to be ground. If any measure as shorted, determine the cause of the short.
7. Measure the resistance between ground and the GRD pin adjacent to VM1N. This pin should measure open. If it does not lift the 40 conductor ribbon connector on the bottom plate and clip pin# 32 on header 1 (H1).
8. Verify from the fixture spreadsheet that the GNDREF connection has been provided for and is routed to the desired pogo. Measure the resistance between this pin and ground.
9. Verify from the fixture spreadsheet the locations of all pogos connected to ground. Verify their connection by measuring the resistance between the carrier board ground and these pogos.
10. Verify from the fixture spreadsheet the locations of all Power VI sense lines, RTNS, and VRTNS, connections. Measure the resistance between pogos designated for these connections and the Power VI header.

1. Using a DMM measure the voltages on all modules. Use the diagram below as a reference. Note: On some carriers the 3.3V may not be available.