Mitsubishi Electric · PCB · Diagnosis
Mitsubishi Electric aircon PCB repair in Singapore
Mitsubishi Electric aircon showing a communication, sensor or board-related fault? We test the indoor PCB, outdoor PCB and inverter or driver stage separately, explain what failed and quote only after diagnosis.
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Signs your Mitsubishi Electric aircon needs a PCB check
These symptoms can involve a control board, but they can also come from wiring, a sensor or another part connected to the board.
The unit has power but will not start
Lights or the controller may still respond while the indoor unit, outdoor unit or both refuse to run normally.
One room or the whole system stops responding
The pattern across rooms helps separate an indoor-board problem from an outdoor or shared communication fault.
A communication or board-related error appears
A Mitsubishi Electric code, blinking light or repeated restart gives us a useful starting point, but it still needs electrical testing.
Examples of Mitsubishi Electric systems we check
These are common examples, not a complete list. We also assess other Mitsubishi Electric systems after checking the indoor and outdoor model labels.
Starmex R32 single-split systems
Starmex R32 multi-split and MSXY-FN indoor units
PLY cassette, PEY ducted and City Multi systems, with scope confirmed from the exact family
Don't see your Mitsubishi Electric model?
Send photos of the indoor and outdoor model labels, plus the error code or a short video of the symptom. We'll confirm the right diagnostic starting point and PCB service scope before arranging the visit.
A board-related code does not always mean a failed PCB
Before ordering model-specific electronics, we check three problems that can make a healthy board appear faulty.
Power or wiring fault
Loose terminals, a damaged interconnect or unstable supply can produce board and communication errors.
Sensor or connected load
A shorted thermistor, motor or valve can pull down a healthy board or make its input look incorrect.
Inverter power stage
On inverter systems, the main control PCB and the IPM or driver circuit are tested as separate failure points.
Mitsubishi Electric error codes related to PCB problems
Your Mitsubishi Electric error code helps us identify where to start. It does not prove that the PCB needs replacement. Open the group that matches where the code appeared.
Indoor unit or controller20 guides
- 0095Mitsubishi Electric AE-200 controller 0095: warning that a metering device may be damaged. What the source table confirms.
- 0100Mitsubishi Electric AE-200 controller 0100: connected equipment abnormality. Record the code and match the service manual before diagnosis.
- 6601Mitsubishi Electric AE-200 controller 6601: m-NET communication polarity has not been established. What the source table confirms.
- 6602Mitsubishi Electric AE-200 controller 6602 meaning varies by model family. Match the source row before diagnosis or parts approval.
- 6603Mitsubishi Electric AE-200 controller 6603: m-NET transmission line is busy and m-NET transmission bus busy. What the source table confirms.
- 6604Mitsubishi Electric AE-200 controller 6604: communication error. What to record and why the matching service manual is needed before diagnosis.
- 6605Mitsubishi Electric AE-200 controller 6605: communication error. What to record and why the matching service manual is needed before diagnosis.
- 6606Mitsubishi Electric AE-200 controller 6606: communication error. What to record and why the matching service manual is needed before diagnosis.
- 6607Mitsubishi Electric City Multi 6607 meaning varies by model family. Match the source row before diagnosis or parts approval.
- 6608Mitsubishi Electric City Multi 6608 meaning varies by model family. Match the source row before diagnosis or parts approval.
- 6920Mitsubishi Electric AE-200 controller 6920: communication error. What to record and why the matching service manual is needed before diagnosis.
- 6922Mitsubishi Electric AE-200 controller 6922: controller communication received-frame ID error. What the source table confirms.
- E0Mitsubishi Electric E0 has model-family meanings for communication error. Match the installed model before diagnosis or parts approval.
- E1Mitsubishi Electric E1 has model-family meanings for pcb / electrical fault. Match the installed model before diagnosis or parts approval.
- E2Mitsubishi Electric PLA-M EA2 cassette E2: remote-controller clock-function error. Record the code and match the service manual before diagnosis.
- E3Mitsubishi Electric PLA-M EA2 cassette E3: remote-controller transmitting error. Record the code and match the service manual before diagnosis.
- E4Mitsubishi Electric E4 has model-family meanings for communication error. Match the installed model before diagnosis or parts approval.
- E5Mitsubishi Electric PLA-M EA2 cassette E5 meaning varies by model family. Match the source row before diagnosis or parts approval.
- E6 / E7Mitsubishi Electric E6 / E7 meaning depends on the model-family source row. Match the installed family before diagnosis or parts approval.
- FB / FbMitsubishi Electric FB / Fb has model-family meanings for pcb / electrical fault. Match the installed model before diagnosis or parts approval.
Outdoor unit3 guides
- FCMitsubishi Electric MUY-TP FC blinking light: pcb / electrical fault. Record the code and match the service manual before diagnosis.
- U5Mitsubishi Electric U5 meaning depends on the model-family source row. Match the installed family before diagnosis or parts approval.
- UbMitsubishi Electric MUY-TP Ub blinking light: fin-temperature or inverter-board-temperature protection. What the source table confirms.
Whole-system faults15 guides
- 6201Mitsubishi Electric Lossnay RVXT3 6201: PZ-62DR remote-controller circuit-board failure. What the source table confirms.
- 6202Mitsubishi Electric Lossnay RVXT3 6202: PZ-62DR remote-controller clock or circuit-board failure. What the source table confirms.
- 6801Mitsubishi Electric Lossnay RVXT3 6801 blinking light: PZ-43SMF-E remote-controller communication error. What the source table confirms.
- 6831Mitsubishi Electric City Multi 6831: communication error. Which fault it is depends on your model, so check the table before booking a repair.
- 6832Mitsubishi Electric City Multi 6832: communication error. Which fault it is depends on your model, so check the table before booking a repair.
- 6833Mitsubishi Electric City Multi 6833: communication error. Which fault it is depends on your model, so check the table before booking a repair.
- 6834Mitsubishi Electric City Multi 6834: PZ-62DR start-bit detection. Whether it is safe to keep running, and what to send before a repair.
- E8Mitsubishi Electric E8 has model-family meanings for communication error. Match the installed model before diagnosis or parts approval.
- E9Mitsubishi Electric MUY-TP E9 has model-family meanings for communication error. Match the installed model before diagnosis or parts approval.
- ECMitsubishi Electric MUY-TP EC blinking light: indoor/outdoor communication receiving error. What the source table confirms.
- U6Mitsubishi Electric U6 meaning depends on the model-family source row. Match the installed family before diagnosis or parts approval.
- U8Mitsubishi Electric U8 meaning depends on the model-family source row. Match the installed family before diagnosis or parts approval.
- U9 / UHMitsubishi Electric U9 / UH meaning depends on the model-family source row. Match the installed family before diagnosis or parts approval.
- UFMitsubishi Electric MUY-TP UF meaning depends on the model-family source row. Match the installed family before diagnosis or parts approval.
- UPMitsubishi Electric UP meaning depends on the model-family source row. Match the installed family before diagnosis or parts approval.
Codes that depend on the exact model22 guides
- 04 / LED 6xMitsubishi Electric 04 / LED 6x: serial signal. Whether it is safe to keep running, what to send, and the checks that confirm it.
- 06 / LED1 lit, LED2 6xMitsubishi Electric 06 / LED1 lit, LED2 6x blinking light: pcb / electrical fault. Which fault it is depends on your model.
- 06 / LED1 lit, LED2 7xMitsubishi Electric 06 / LED1 lit, LED2 7x blinking light: nonvolatile memory data. What to send before booking a repair.
- 09 / LED1 lit, LED2 11xMitsubishi Electric 09 / LED1 lit, LED2 11x blinking light: communication error. Which fault it is depends on your model.
- 10 / LED1 lit, LED2 12xMitsubishi Electric 10 / LED1 lit, LED2 12x blinking light: pcb / electrical fault. Which fault it is depends on your model.
- 13 / LED1 lit, LED2 15xMitsubishi Electric 13 / LED1 lit, LED2 15x blinking light: pcb / electrical fault. What to send before booking a repair.
- 24 / LED1 lit, LED2 11xMitsubishi Electric 24 / LED1 lit, LED2 11x blinking light: communication error. Which fault it is depends on your model.
- 25 / LED1 lit, LED2 12xMitsubishi Electric 25 / LED1 lit, LED2 12x blinking light: pcb / electrical fault. Which fault it is depends on your model.
- 0403Mitsubishi Electric City Multi 0403: communication error. Which fault it is depends on your model, so check the table before booking a repair.
- 4225Mitsubishi Electric City Multi 4225: control power-supply fault. Whether it is safe to keep running, and what to send before a repair.
- 4226Mitsubishi Electric City Multi 4226: low bus voltage at startup. Whether it is safe to keep running, and what to send before a repair.
- 5305Mitsubishi Electric City Multi 5305: fan-board current-sensor fault. Whether it is safe to keep running, and what to send before a repair.
- 5306Mitsubishi Electric City Multi 5306: pcb / electrical fault. Whether it is safe to keep running, what to send, and the checks that confirm it.
- 7110Mitsubishi Electric City Multi 7110: communication error. Whether it is safe to keep running, what to send, and the checks that confirm it.
- EdMitsubishi Electric Ed blinking light: communication error. Whether it is safe to keep running, what to send, and the checks that confirm it.
- EFMitsubishi Electric EF meaning depends on the model-family source row. Match the installed family before diagnosis or parts approval.
- FR03 / recall upper lamp 3xMitsubishi Electric FR03 / recall upper lamp 3x: serial signal from outdoor unit not received. What to send before booking a repair.
- FR12 / recall upper lamp 12xMitsubishi Electric FR12 / recall upper lamp 12x: indoor control PCB nonvolatile memory read fault. What to send before booking a repair.
- PUY-WIRINGMitsubishi Electric PUY-WIRING blinking light: miswiring of indoor/outdoor connecting wire. What to send before booking a repair.
- Starmex 4 blinksMitsubishi Electric Starmex 4 blinks: indoor control system. Whether it is safe to keep running, what to send, and the checks that confirm it.
- Starmex 7 blinksMitsubishi Electric Starmex 7 blinks: outdoor control system. Whether it is safe to keep running, what to send, and the checks that confirm it.
- Starmex continuous blinkMitsubishi Electric Starmex continuous blink: miswiring or serial signal. Whether it is safe to keep running, and what to send before a repair.
Do not see your code here? Send a photo of the display and both model labels. Mitsubishi Electric codes can mean different things across model and system families.
What happens during a Mitsubishi Electric PCB check
The aim is to give you a clear diagnosis and a sensible repair decision, not an automatic parts quote.
Send us the model and symptoms
Share the Mitsubishi Electric indoor and outdoor model numbers, any error code, which rooms are affected and what happened before the fault.
We test the likely causes
We check the power supply, communication wiring, sensors, connected loads, indoor and outdoor boards, and inverter drive where fitted.
You receive the finding and quote
We explain what failed, whether the correct part is available and whether repair or replacement is the better use of your money.
We repair and test the system
After approved work, we run the Mitsubishi Electric system through a full cycle and confirm that the original symptom or error has cleared.
Is Mitsubishi Electric PCB repair worth it?
It depends on the confirmed fault, system age, parts availability and the condition of the rest of the aircon.
Parts and timing
Starmex parts for current and recent residential families are generally available. Older commercial or discontinued boards require an exact model and part-number check.
Our recommendation
PCB repair is usually sensible when the rest of the system is healthy, the exact board revision is available and testing has ruled out wiring, sensors and connected loads. Mitsubishi Electric systems commonly have a service life of Starmex residential: 8–12 years. For a system starmex over 12 years, parts sourcing becomes harder for older Starmex models. Major component failures usually favour replacement, especially if efficiency has noticeably dropped.
If replacement is the better option, we can compare the repair quote with a suitable new system instead of asking you to keep repairing an uneconomical unit. See our aircon system replacement process.
Why diagnosis matters on Mitsubishi Electric aircon
Mitsubishi Electric boards are model-specific and one fault can involve the indoor board, outdoor board or inverter stage. Testing the circuit first helps avoid ordering the wrong electronics.
A Mitsubishi Electric PCB fault we check carefully
Mitsubishi Electric uses both display codes and lamp patterns across its families. We match the observed display to the model before deciding whether the fault sits indoors, outdoors or in communication wiring.
Useful Mitsubishi Electric repair references
Workmanship warranty
We stand behind the repair we carry out, and we are straight about the part of the cover we do not set ourselves.
Labour
30-day labour warranty. If the same fault returns from the repair we did, we come back and the labour is on us, with no second diagnosis fee.
Parts
Parts follow whatever warranty the distributor sets for that component, so the term varies by part. We tell you the coverage before you approve the quote.
Frequently asked questions about Mitsubishi Electric PCB repair in Singapore
What are the signs of a Mitsubishi Electric PCB problem?
How do you confirm a Mitsubishi Electric PCB fault?
Is a Mitsubishi Electric error code enough to order the PCB?
Should I repair or replace my Mitsubishi Electric aircon?
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Ready to get started?
Tell us what’s going on. Symptoms, setup, photos, anything we should know. We’ll assess and come back with the right next step.