*investigation x-review dhr.X-inspect returned samples.*analysis and findings complaint #(b)(4).Distribution history: this complaint unit was manufactured at csi on 1/13/2020 under wo #269847 & 269837 and shipped on 3/19/2020.Manufacturing record review: dhr's 269847 & 269837 were reviewed and no non-conformities, related to the complaint condition, were noted.Service history record: no additional service history records found for this unit.Historical complaint review: a review of the 2-year complaint history showed a couple similar reported complaint conditions.No additional detail on what the issue could be was available on the complaints.New boards were put in the units and the old ones were discarded.Product receipt: based on log 94328, this unit was at csi on (b)(6) 2020.The complaint unit was returned on a repair.Visual evaluation: visual examination of the complaint unit revealed no physical damage.However, the housing seam between the front plate and the chassis was noted to have a black char residue.Once opened, the source of the char was internal damage to the display board components, r9 & r14.Functional evaluation: complaint unit was functionally evaluated and found not to function properly.Root cause : an initial investigation by technical operations (csi's engineering dept.) has indicated resistors r9 and r14 were burnt out due to being exposed to current outside their rating.The source of the power burning out the resistors has been determined to be t6, one of the transformers on the main board.The root cause of this issue has been attributed to under rated resistors.*correction and/or corrective action the customer was provided with a new generator unit.The returned unit was evaluated by technical services and confirmed this unit was fitted with a screened board for t6 irregular readings.The board had no irregular readings indicating the issue will need to be mitigated at the resistors.Engineering will be increasing the rating for the affected resistors per capa (b)(4).New boards are to be fitted with the new resistors once the ecn is complete.*review and closure fault code: component failure code: manufacturing defect *preventative action activity reference capa (b)(4).
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