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Manufacturer narrative: the device was returned to bmc for investigation and customer complaints were confirmed.When the reported malfunction occurred, the device emitted audible and visual alerts to notify the user that the device is unable to output the setting pressure, which triggers the inherent safety design of the device.The bmc inspection of the returned device found that after the device was powered on, a "77-03" (motor status abnormal) prompt appeared on the screen, and the device emitted a beeping sound.After disassembling the device for investigation, it was discovered that the surface-mount resistor rm37 on the pcba was broken, causing the fan fail to work properly.Eventually, the equipment was unable to output the setting pressure.The fracture of resistor rm37 is probably attributed to factors including: mechanical stress incurred during handling or use (e.G., impact), thermal stress during the pcb assembly process (e.G., soldering temperature excursions),an inherent latent defect within the component itself (e.G., micro-cracking),or a combination of these factors.Based on current post-market surveillance data, this failure mode is considered an isolated occurrence.As such, it is not presently classified as a systemic design-related issue.Bmc will continue to monitor field performance for similar events.Should future data indicate an increasing trend in the recurrence rate, a comprehensive re-evaluation will be promptly initiated, and appropriate engineering corrective actions will be implemented.
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