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The investigation was performed by considering complaint description, customer service reports, system history, & system log files.During the procedure, the customer was unable to do fluoro imaging on a biplane system (plane a and b) as expected.The small focus x-ray release failed repeatedly, though not continuously, and there was no automatic switch to the large or micro focus.Due to the issue customer decided to transfer the patient to another hospital to complete the procedure.There was no health issues reported as a result of this incident.Upon analyzing the log files, it indicated an error related to the small focus of the x-ray tube in plane 'a'.The system showed an error message ¿dose lower than 5% and high voltage remaining active after the pulse ended¿.Normally, the emitter has symmetrical distances to the boundary plates.If the distances are not symmetric it is probable that the emitter extends on thermal load and then may touch the focal boundary, which can cause various issues including arcing events.As a consequence, fluoro x-ray requests were aborted repeatedly though not continuously, thereby disrupting the fluoro imaging process.X-ray tube has three focal points.The issue was only with the plane ¿a¿ small focus, the small focus had not failed completely.Due to which the system did not automatically switch over to large focus.The user could do the switch over manually based on the organ protocol (ogp) in order to get the required image quality.If the small focus had failed completely, the system would have switched to the large focus automatically.Large focus was available for image acquisition based on the limited acquisition programs configured and to high thicknesses in case of acquisition programs configured for automatic focus switchover.This type of failure (focus failure with an intermittency preventing the activation of automatic error management mechanisms) has a rare occurrence.The issue was only in the plane a small focus, plane b was working as intended.Customer decided not to use the system.A customer service engineer (cse) was on site for troubleshooting, the customer was informed about the defective small focus.The organ protocols were adapted to use the large instead of the small focus.After troubleshooting, the system was restored to normal operation.The relevant root cause for the non-conformity was determined to be a defective x-ray tube of plane ¿a¿.Customer did not agree and chose not to replace the x-ray tube.A possible error accumulation or even a systematic error, which leads to a corrective action of the install base, could not be determined by the investigation.
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