| Description: | The ice storm of 30-31 January, 2002 shut down the AOS for ~2 weeks. A controlled
power-up of the system found a problem with the ozone monitor. Smoke was observed to come from
the ozone instrument, at which time it was shut down.
The ozone monitor was removed from the AOS for remote troubleshooting. The cause of the
smoke was identified as being from underneath a printed circuit board. At that point, Site
Ops staff were requested to send the unit to Boulder for additional troubleshooting.
NOAA staff received the unit on 20 February 2002.
After a brief inspection, the cause of the smoking was discovered. A one-half inch hole
was burned completely through the motherboard. The determination was made that this could
not be repaired at the NOAA facility, and a purchase order was initiated to return the
unit to Dasibi, Inc. (the manufacturer), for repair/replacement of the motherboard.
On 4 March, 2002, NOAA personnel received the OK from ARM to return the instrument to
Dasibi, Inc. for service. Dasibi, Inc., received the unit on or around 8 March, 2002. The
manufacturer was to test the unit, repair or replace the damaged motherboard, and
calibrate the unit according to the NIST standard protocol.
On 8 May, 2002, NOAA personnel emailed SGP Site Ops personnel and asked them to check on
the status of the repair, which was taking longer then expected. Upon trying to contact
the manufacturer, it was discovered that they went out of business. The return of
instruments from the manufacturer to customers was being handled by a contract company. The
ozone monitor arrived back in Boulder, in an unrepaired state, on or about 1 July 2002.
Since there were few other options, NOAA personnel undertook the difficult task of
repairing the motherboard. This required the re-routing of several electrical conduits from the
burned area in the multilayer board to other acceptable places on the board. This took
a considerable amount of electronics technician time and effort. After the motherboard
was repaired, extensive testing was required to verify that the repair was done
successfully and that other problems were not caused in the unit by the board burning..
The repair was deemed successful on 24 September, 2002. The unit was shipped back to the
SGP site immediately thereafter. It was installed during a NOAA AOS maintenance visit on
1 October, 2002. |