Action Summery
Description: Class 2 via problems
corrective action additional qa inspection at
LBNL for initial run
corrective action improved drilling process at
Data Circuits (holes
per drill reduced from 750 to 500,
no resharpened drills, additional qa inspection
board disposition non conforming boards - held
permanently at LBNL
boards affected sn V5_00105, V5_00111, V5_00137, V5_00165,
V5_00170, V5_00183 (At least three boards)
Description: ATWD variable timing
corrective action ATWDs replaced
corrective action additional screening of
ATWDs prior to loading
board disposition held at LBNL pending
appropriate use
boards affected sn yyy,zzz (number unknown)
Description: Localized overheating of CR15, CR16
corrective action Replace affected parts
corrective action Measures to reduce local
heating during reflow
board disposition Boards routed through production
without restriction
boards affected sn V5_00324, V5_00511
Description: Serial ADC malfunction at temperatures below -40°C
corrective action Replace malfunctioning serial
ADC
corrective action A change of multi-channel serial
ADC is under consideration for a future version of the DOM MB
board disposition Boards routed through production
without restriction
boards affected sn:
Description: Local Coincidence Malfunction [Power Splitter]
corrective action Replace faulty component
board disposition Boards routed through production
without restriction
boards affected sn: (at least four
occurrences)
Description: Local Coincidence Malfunction [Transformer]
corrective action Replace faulty component
board disposition Boards routed through production
without restriction
boards affected sn: (at least three occurrences)
Description: Local Coincidence Malfunction [LC_UP_+ net]
corrective action Repair with jumper wire on
board surface
corrective action Enhancement of PCB traces and/or
routing is under consideration for a future version of the DOM MB
board disposition non conforming boards - held
permanently at LBNL
boards affected sn: (two occurrences)
Description: Cloudy solder mask
corrective action Test board in normal fashion.
corrective action Ask vendors for added vigilance in
board manufacture or processing.
remarks
Class III standards do not comment on cloudiness or discoloration in
solder mask. We will be conservative.
board disposition non conforming boards - held
permanently at LBNL
boards affected sn: V5_00560, V5_00561, V5_00562,
V5_00563, V5_00565, V5_00566, V5_00567, V5_00569, V5_00584, V5_00585
Description: Temperature defendant boot failure
corrective action Generalized boot coordination
through CPLD mediated control of boot hand-shake signals.
corrective action For future DOM MB production,
or for DOMs which are unsealed, reload CPLD with latest release.
corrective action For previously sealed DOMs,
use mitigation of power cycling in 5 to 20 second window.
board disposition Boards with updated firmware (later than
1.7) routed through production
without restriction
boards affected All boards delivered by LBNL
after September 17.