Nihon Kohden ECG-9132K: dim, low-contrast LCD
What happened
The LCD of a Nihon Kohden ECG-9132K became barely readable. The question in the case was whether brightness/contrast can be adjusted at all, or whether the display module must be replaced.
What was checked
- The engineers first went to the service manual: its block diagram shows a dedicated brightness/contrast adjustment stage, so a software-accessible setting looked likely.
- Before condemning the display, they confirmed that the adjustment exists in the manufacturer's service documentation rather than in the normal user menu.
Cause
Reported in the case: no hardware fault was found. The panel was simply set to a low contrast/brightness, and this adjustment is not reachable from the normal user menu, so the unit only looked degraded.
What was done
The fix was a procedure from the manufacturer's service documentation, done by authorised personnel: contrast and brightness were adjusted to a readable level and the unit was restarted. No display replacement was needed; per the case, the dim display issue was fully resolved.
Safety
Before returning an ECG machine to clinical use after any adjustment or service access, run the electrical safety checks — protective earth continuity and leakage current — and confirm a normal recording on a test subject or simulator.
Lesson: A dim display is often a settings issue, not a failed part — check the manufacturer's service documentation for adjustment procedures before ordering a replacement.
Covered in the course: Fault-Finding Method for Medical Equipment →
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.