The following are detailed steps and precautions for performing a continuity test with a handheld digital multimeter, combining both the beep and resistance modes:

• Turn the function knob to the beep mode (usually symbolized by a "◯") or the diode/continuity/combination mode.
• Some models require a short press of the function key to switch to continuity mode (for example, on the Uni-T UT61D+, this requires pressing the yellow button).

• Insert the black test lead into the "COM" jack and the red test lead into the "VΩ" jack.
• Before testing, short-circuit the test leads and confirm that the beep sounds and the displayed value is close to 0Ω (indicating a normal test).

• Touch the red and black test leads to each end of a wire. If the beep sounds continuously and the displayed value is less than 1Ω, the wire is conductive.
• If the display reads "1" or "OL" (overrange) and there is no beep, there is a break.

• Touch the test leads to the contacts at both ends of the switch. A buzzer should sound when the switch is closed and display "1" when it is open.

• With the power off, use the beeper to measure the resistance between the live/neutral wire and the ground wire:
  Beep or resistance close to 0Ω = leakage
  No response and "1" displayed = normal insulation

• Connect the red test lead to the positive terminal (without the ring end) of the diode and the black test lead to the negative terminal (with the ring end). A normal conduction voltage drop (0.5-0.7V) should be displayed. Bidirectional conduction or no conduction indicates damage.

• Test both ends with the beeper. If it sounds, it is intact; if it does not, it is blown.