ELI 250

1. Make sure the patient is safe — swap in a backup unit if you need to.
2. Reproduce the complaint yourself and write down exactly what you see (screen, alarm, code).
3. Check power, battery, cables, accessories, and settings before ordering parts.
4. Then open the service manual above and follow its troubleshooting section.

Backlight on with AC but nothing displayed source ↗

• Check the AC fuses
• Does it boot on battery? Yes: AC supply fault, replace motherboard. No: replace motherboard and check battery
• Reseat, then replace, the keyboard/LCD cable

LCD blank but key tones sound source ↗

• LCD fault: replace the LCD

Works on AC but not on battery source ↗

• Check the battery fuse and connections; replace battery
• Power Supply Test: off current <40 µA, on current <250 mA, charger 13.0–14.0 VDC with the AC LED on

Function keys show but no waveform source ↗

• Front-end-to-motherboard comms: replace the cable, then the front-end board, then the motherboard

Keyboard dead / LCD frozen source ↗

• Remove AC; hold On/Off 10 s; wait 10 s and restart
• Or remove the battery fuse for 10 s

RS-232 or modem transfer fails source ↗

• Match the baud rate to the receiving system; otherwise the cable or motherboard
• Modem: verify the phone number and init string

Print quality / writer issues source ↗

• Writer test: Alt+Shift+RHY on AC
• Check the 200 mm line ±2 mm (motor), missing dots (print head) and the cue sensor trace

Speaker volume or date/time not retained source ↗

• F6 More → 3 Date & Time → Alt+Shift+C → Volume 0–8; replace the speaker, then the motherboard
• If date/time isn't kept after saving with F5, replace the motherboard

Leads off / bad waveform source ↗

• Swap patient cable, then harness, then ECG board

Power/battery source ↗

• Check AC fuses; fewer than 10 reports per charge = replace battery