DOM MB Diagnosis page

Board ID:

Rev 5.0 SN 0385

Source:

From STF testing crew

Symptoms:                            

Fails Local Coincidence Loopback tests

Analyst(s):

G. Przybylski

Analysis Procedure(s):

Load and execute ?DO lctestboth wait20ms LOOP, with terminated pair ports,  and probe LC circuit.
Waveform at R75 (driver) look somewhat anomylous.
Waveform at TP10 anomylous; smooth and broadened; same polarity as driver.
Waveform at TP3 anomylous; Excessively rapid decay.
Lifted lead of T3.  TP3 signal reappears.  Replace T3 and run STF tests with favorable results.

Root cause:

Found faulty T3; no evidence of solder bridges.

Mitigation:

Replace defective part, and retest. Run complete STF.

Disposition:

Sent to Helen for clean-up,  and rerouting into the normal production queue.

Any Other Information:

none