Repair Workshop: voltage regulator fault

Pick the symptom; at every step we show what to measure, where and how. An autotransformer doesn't isolate: the whole board sits at mains voltage, so don't skip the safety warnings.

Step 1free trial: 3 steps left

Before you start: every part of this unit is at mains potential

🔧 How to measure

An autotransformer is not an isolation transformer: the output, input and neutral are tied together through the winding. Even the 12 V relay side can be dangerous relative to earth. Disconnect every load from the output, measure one-handed, and unplug and switch off before any resistance measurement. The unit is heavy (10 kVA ≈ 20–30 kg): don't tip it over when opening the cover.

⚠ Mains voltage present: power the board through an isolation transformer, measure one-handed, and don't touch parts before discharging the bulk capacitor.

On a healthy board, at this point:

Multimeterinput tap 220 V

🔒 This content is in the repair pack

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Repair pack: 5,000 ₺, members get 10% off → 4,500 ₺. Or 1-week access for 1,000 ₺.

Want to see how the board works first? Go to the How it works page →