BTL BTL-08 ABPM: measurement aborts and compressor never starts
What happened
On this ambulatory blood pressure monitor every measurement attempt failed: the inflation compressor stayed off, the unit stopped with error (1) as reported in the case, and then set error (99) — no automatic measurement until the device is reprogrammed.
What was checked
- The engineers checked the compressor supply and control circuits and found them intact.
- They also confirmed the compressor motor itself was healthy: when actuated directly at the driver stage as a diagnostic step, it spun normally.
- With the pump path effectively ruled out, the pressure sensing line came under suspicion — and the pressure sensor (identified in the case as FGN-607PGSR) was found to have come away from the board.
Cause
A detached pressure sensor. Without a valid pressure signal at start, the monitor aborted the measurement with error (1) and blocked automatic measurement with error (99). The compressor and its driver were fine — the pump was simply never commanded because the unit could not confirm pressure.
What was done
A straight hardware repair: the sensor was re-seated and re-soldered to the board, restoring the pressure signal; after that the monitor started and completed measurements normally. Reported solved in this case.
Safety
Disconnect the battery before any soldering on the board, and before the monitor returns to patients verify cuff pressure accuracy and the overpressure protection against the manufacturer's specification, since the repair touches the inflation and pressure-measurement path.
Lesson: A "compressor doesn't run" fault is often not about the compressor: without a valid pressure signal at start the monitor will refuse to inflate, so prove out the pressure feedback path before condemning the pump.
Covered in the course: Patient Monitor Service — Level 2: Fault-Finding →
Written from an anonymised case shared by service engineers. It is not a manufacturer instruction and grants no authorisation. Independent note; names are trademarks of their owners.