For the Agilent 66311B DC power supply that frequently triggers overvoltage protection, you need to focus on checking the following components during repair:

1. Overvoltage Protection (OVP) circuit components: Inspect reference voltage sources, comparator ICs, and threshold-setting resistors/capacitors. Drift or damage to these parts may cause the OVP threshold to deviate, leading to frequent triggers.
2. Output voltage feedback loop: Check voltage divider resistors in the feedback path, operational amplifiers, and error amplifiers. Faults in these components can result in inaccurate voltage detection, triggering false OVP alerts.
3. Power stage components: Examine output MOSFETs, diodes, and other power devices. Failures here may lead to voltage spikes that activate the OVP.
4. Wiring and connections: Verify if there are loose, corroded, or damaged connections in the output or feedback circuits, as these can cause unstable voltage signals and false triggers.
5. Control logic components: Check the control board's microcontroller or related logic circuits for abnormal operation that incorrectly activates the OVP.

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