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Error code reference
Magic Chef Cooktop Error Code U400
Secondary voltage of the power unit too high (primary > 300 V); control unit cuts off after 1 second and gives a long tone.
SourceMagic Chef Range - Tech Sheet: 31FA-7-CNp. 3
Diagnostic procedure
The full U400 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
Disconnect power, then connect to correct mains voltage.
SourceMagic Chef Range - Tech Sheet: 31FA-7-CNp. 3
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
1 manual in the MyPros+ library documents this code for Magic Chef cooktop.
Models covered by the manuals that document this code
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