Blink count: 1
Upper/left operation lamp flashes 1 time repeatedly (about 0.5-second cycle)
Typical causes
- Room thermistor short/open circuit
- Thermistor connector issue
- Indoor PCB sensor input fault
Mitsubishi Electric (Starmex) Aircon Blinking Light Patterns
Use this Mitsubishi Electric (Starmex) blink table to match patterns and narrow next checks before booking.
Before you use this tool
This is a blink-pattern guidance table, not a model-exact diagnosis. Pattern meaning can vary by controller and series. If your controller shows a direct code (for example `CH21`, `U4`, `E6`), use the error-code guide for a faster match.
Safety warning
Stop using the unit and contact a technician if the breaker trips repeatedly, you smell burning, see sparks, hear loud electrical buzzing, or water is leaking from places it normally should not.
Mitsubishi Electric (Starmex) blink guide
Includes common SG residential blinking-light patterns with what they usually indicate and typical causes. Not every blink pattern maps to an error code.
Blink count: 2
Operation lamp flashes 2 times, then about 2.5 seconds OFF, then repeats
Typical causes
- Indoor coil thermistor short/open
- Thermistor harness fault
- Indoor board sensor circuit issue
Blink count: 3
Operation lamp flashes 3 times, then about 2.5 seconds OFF, then repeats
Typical causes
- Indoor-outdoor serial communication issue
- Control wiring instability
- Indoor or outdoor PCB signal fault
Blink count: 4
Operation lamp flashes 4 times, then about 2.5 seconds OFF, then repeats (inverter models)
Typical causes
- Indoor fan feedback abnormality
- Indoor PCB failure
- Fan motor drive/control issue
Blink count: 6
Operation lamp flashes 6 times, then about 2.5 seconds OFF, then repeats (inverter models)
Typical causes
- Outdoor thermistor short/open
- Outdoor thermistor connector fault
- Outdoor PCB sensor-input issue
Blink count: 7
Operation lamp flashes 7 times, then about 2.5 seconds OFF, then repeats (inverter models)
Typical causes
- Indoor-outdoor communication receiving error
- Control wiring fault
- Indoor or outdoor PCB fault
Blink count: 11
Operation lamp flashes 11 times, then about 2.5 seconds OFF, then repeats
Typical causes
- Indoor fan feedback signal missing
- Fan motor fault
- Indoor drive/PCB issue
Blink count: 14
Operation lamp flashes 14 times, then about 2.5 seconds OFF, then repeats
Typical causes
- Low refrigerant condition
- Unit pump-down/short-cycling state
- Outdoor fan lock leading to circuit stress
Blink count: Not applicable
When operation lamp is blinking, remote CHECK mode can display a 2-digit error code
Typical causes
- Indoor unit has detected a fault
- User initiated CHECK mode for diagnosis
- Need to identify exact code before service call
Not sure how to read your Mitsubishi Electric (Starmex) blink pattern?
Send a short blink video and your model sticker. We'll advise the next step before any work is recommended.
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