DOM MB Diagnosis page
Board ID:
V5.0-00171, from STF
Source:
STF testing; George
Symptoms:
Slow read-out, or slow STF.
Analyst(s):
G. Przybylski
Analysis Procedure(s):
Reloaded CPLD, Configuration
memory and Flash memory.
Attempt to run STF produces an unusually high number of front-end
related errors.
The front end DACs are found to all read zero.
The SPI serial clock, and chip selects are OK. The data line is stuck
low on U59, U67.
U29, U31 function normally.
Identified open PCB trace near C414. (see picture below)
Bridge open trace with jumper wire soldered between vias.
Root cause:
Faulty PCB trace, apparently not
identified during production testing, or PCB trace failure arising
during reflow.
Mitigation:
Repair trace. Investigate possible 'coverage' problem with PCB and
loading vendor.
Disposition:
Repair with jumper wire.
Mark as DO NOT DEPLOY
Any Other Information:
Traveler
