LAT  Electronics, Data Acquisition & Instrument Flight Software

  Subsystem Manager:  Gunther Haller

 

Important: EM2 test-stand hardware components are NOT compatible with hardware supplied for EM1 test-stands. Do not mix TEM/TEM-PS/Transition Card EM1 with EM2 hardware. Hardware for EM2 is marked "EM2" on the TEM, TEM-PS, VME Transition Card and LCB supplied.

Documents:

The documents are in the process of being transferred to the LAT-DOC system for official release, please retrieve them from LATDOC's.

Here are applicable document numbers and selected copies of the documents in the release cycle (use them with caution).

Note that we do not perform impedance/short/open/voltage measurements on all pins, but test functionality of the system. The "safe-to-mate" test is the responsibility of the sub-system.

Calorimeter:

EGSE-CAL-FM TESTSTAND #1

LAT Quality Assurance

Performance & Safety Assurance LAT NCR Report

The following Nonconformance Report # 00133 was submitted on 07/14/04 13:37:58

 

Entered by Ludvik, Jeffrey - jsludvik@slac.stanford.edu

 

Found by:  Customer Complaint

Type of Nonconformance:  Minor

Discrepancy Level:  Non-Flight Hardware

Sub-System:  Electronics (ELEC)

Item Description:  EGSE CAL FM Teststand#1

Supplier: 

Location: 

Drawing/Rev #:   

Lot/Heat #: 

Serial #: 

Test Procedure/Rev #: 

 
Description of Nonconformance:  NRL found bad data from TEM that suggested a short between data lines. TEM/TPS modules of CAL FM Teststand #1 were returned to SLAC for repair. ASICs on TEM were not prescreened before loading and the existing software testing did not have complete coverage of all possible problems. A new test was developed that had more coverage and when the unit was tested the error that NRL found was highlighted by the software. GCCC ASIC U4 was found to have an internal short between pins 71 and 72. The action taken was GCCC ASIC U4 was replaced. After replacement, TEM/TPS unit completed and passed all performance testing and is being shipped back to NRL.
       

Disposition Area

Defect Code:  050 Electronic/Electrical

Disposition:  Rework 
(Valid  dispositions:  Rework, Repair, Use-as-is, Reclassify, Return to Vendor, Scrap, or Documentation Change)

Disposition Instructions:  
08/09/04 08:11:23 marsh

The ASIC GCCC U4 was replaced. The newly developed software which has more full coverage testing was used to test the TEM. The TEM/TPS unit was fully retested and passed all performance testing requirements per documents LAT-TD-03415 and LAT-TD-01652. The unit was sent back to NRL on 7/15/04.
08/09/04 09:54:15 marsh

NCR closure approved by David Nelson, DAQ Engineering, and Y.C. Liew, LAT Quality Engineering (e-mails on file).

Root Cause: 
The ASICS installed in the TEM boards were not prescreened (normal yield was expected to be 95%). Also the existing software did not have complete full coverage testing. The ASIC GCCC U4 was found to have an internal shorts between pins 71 and 72 when tested to the newly developed software.

Action taken to Preclude Recurrence of Discrepancy: 
Test software was modfied to ensure a more robust electrical performance test is performed on the boards.