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Error code reference
LG Air Conditioner Error Code 77
Fan over current error: fan output current exceeds 5A for 40ms.
SourceLG Air Conditioner - Service Manual: Heat Recovery Outdoor Unit R410A (ARUB80LT2)p. 145
Diagnostic procedure
The full 77 procedure
Step 1 is visible so you can confirm you are on the right page. The remaining steps, the ones that tell you whether to actually replace a part, unlock with any pass.
MyPros+ · DiagnosticsStep 1 preview
1
First diagnostic step
Check outdoor unit fan motor assembly condition and locking; check motor phase resistance (16.8Ω ±5% at 75°C).
SourceLG Air Conditioner - Service Manual: Heat Recovery Outdoor Unit R410A (ARUB80LT2)p. 145
More steps, wiring diagram references, and verified part numbers
Includes expected resistance and voltage values, connector pinouts, and supersession notes for replacement parts.
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Where this code is documented
2 manuals in the MyPros+ library document this code for LG air conditioner.
Models covered by the manuals that document this code
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