A baby monitor lets parents rest while the little one sleeps in another room. But when it starts hissing, losing the connection or switching itself off, that peace of mind is gone. A missed cry is not something anyone wants to test in real life.
Most minor faults come down to power: a worn battery, oxidised contacts in the battery compartment or a poor connection in the charging socket. You can usually sort these out at home in half an hour.
What you will need
Important: Before any work, switch off both units, unplug the adapters and remove the batteries. Never spray products near the baby or the cot: work in another room and ventilate it. If the monitor is under warranty, do not open the casing.
Step 1
Clean the casing
Dust and greasy fingerprints build up on the speaker, microphone and camera lens and degrade sound and picture. Wipe the casing with a slightly damp or antistatic cloth, making sure no water runs into the openings. An antistatic cloth also helps reduce dust build-up.
Gently blow out or brush the speaker and microphone holes with a dry soft brush. Do not use abrasive cleaners or solvents on the casing.
Step 2
Check the power supply and adapter
The cause is often simple: a damaged cable, a loose socket or the wrong adapter with a different voltage. Inspect the cord along its length, check that the plug sits firmly and try another compatible adapter with the same ratings as printed on the unit.
If the parent unit only works on mains power and drains quickly, the battery has most likely reached the end of its life.
Step 3
Open the battery compartment and replace the battery
Unscrew the compartment cover. If the screw has seized because of humidity in the nursery, put a drop of WD-40 Multi-Use on the tip of a cotton bud and touch only the screw head, wait a few minutes and undo it. Wipe away any excess straight away.
Fit an original battery or one that exactly matches the voltage and capacity. If the unit takes standard batteries, use fresh ones of the same make and observe the polarity.
Step 4
Clean the contacts
A white deposit or darkening on the springs and plates of the compartment, or in the charging socket, interrupts the power supply. Spray a little WD-40 Specialist Contact Cleaner onto a cotton bud or directly onto the contacts from close range and wipe until the metal shines.
It is non-conductive, evaporates fast and leaves no residue, so it is suitable for sensitive electronics. Let everything dry completely, a few minutes, before refitting the battery and switching on.
Step 5
Restart and re-establish the link
Switch both units on and re-pair them following the manufacturer's instructions. Hissing and dropouts are often caused by interference from a Wi-Fi router, microwave or cordless phone nearby. Place the baby unit 1-1.5 m from the cot and away from other wireless devices, and change the channel if your model allows it.
If the monitor is still unreliable after all these steps, take it to a repair centre. Your child's safety depends on it, so this is no place for soldering experiments.
Tip: In winter, when indoor air is dry but window sills and balconies are cold, moisture can condense on cold contacts. Keep the units off the window sill and treat the contacts with contact cleaner every few months to stop them oxidising.
What next
Wipe the monitor once a week, check the battery contacts every 2-3 months and keep a spare set of batteries. WD-40 Specialist Contact Cleaner is just as handy for remote controls, battery toys and other small devices around the home.
These uses come from the experience of WD-40 users in many countries. Always follow the instructions and warnings on the product label.
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