Power out in one room? Here's the fault tree we work.
When the rest of the house is humming along but one room is dark, the problem is almost always sitting on a single final subcircuit between your switchboard and the affected GPOs or lights. We get this call from Figtree, Corrimal, Fairy Meadow, Berkeley and Port Kembla nearly every week. Here's how we diagnose it, in the order we actually do it.
The four most common causes - in the order we check them.
1. Tripped RCD or circuit breaker.
On any home built or rewired in the last fifteen years, we start at the switchboard. We look for an RCD or RCBO in the mid-position (not fully off, not fully on), a breaker that's clearly tripped, or a neutral bar with a loose connection. About 60% of single-room outages on newer Illawarra estates are exactly this - usually triggered by a failing appliance like an old kettle, a damaged extension lead, or moisture in an outdoor GPO after a southerly blows rain in off the escarpment. We isolate the circuit, test it cold, and only then think about replacing protection.
2. A failed GPO, switch or light fitting.
The next layer is the accessory itself. Power points get hammered over twenty years - heaters and air-con plugs in particular cook the terminations. We pull the suspect GPO, check the back of it for discolouration, burnt insulation, loose screws or a cracked block. Around half the dead-room calls in older Wollongong CBD weatherboards come down to a single GPO with a charred terminal, often the one behind the lounge that has had an oil column heater on it every winter for fifteen years.
3. Cable damage between the board and the room.
If the protection is good and the accessories test clean, we go looking for the cable. In Illawarra roof spaces this is often rodent damage, especially in homes within a block of bushland or the escarpment. We also see nail and screw strikes where a homeowner has hung something heavy without a stud finder. On older Port Kembla and Cringila homes, ageing TPS cable insulation can be brittle enough that an attic crawl during an earlier reno cracked it. We use insulation-resistance testing (megger) to find the fault location rather than guessing.
4. A failed neutral on a shared circuit.
The rarest of the four, but the one that catches inexperienced sparkies. On older homes with shared neutrals across two circuits, a failed neutral can produce half-voltage at GPOs (so a fridge light is dim but won't run), or a circuit that measures live but won't deliver any current under load. We test for this with a clamp meter under load - not just a multimeter on an unloaded circuit, which will read perfectly fine and send you home thinking it's solved.
Why we don't lead with the switchboard on a 2010-era estate.
On a Horsley, Albion Park or Shellharbour estate from the mid-2000s onward, the switchboard is already to a modern spec - split RCDs, properly rated breakers, decent labelling. Starting there wastes an hour. The fault is far more likely to be at the point of use. On a pre-2000 Wollongong CBD or Corrimal cottage with a ceramic-fuse board, that calculus flips and we start at the board because the protection itself is often the weak link and the wiring downstream may need a full safety inspection too.
Quick questions, fast answers.
Is it safe to keep using the rest of the house?
Yes, in most single-circuit faults. The other circuits are independently protected at the board. The exception: if you smell hot plastic, see scorching around a GPO, or hear buzzing at the switchboard, isolate the main switch and call us straight away - that's a job for our 24/7 emergency line, not a next-day diagnosis.
Does Endeavour Energy need to be involved?
Almost never on a single-room fault. Endeavour's responsibility stops at the point of attachment / meter. Anything inside your home is on the homeowner's side and is our work. The exception is if the supply itself is flickering across the whole street, in which case the report goes to Endeavour first.
Will this need a switchboard upgrade?
Sometimes - particularly if the diagnosis reveals you have no RCD coverage at all on power circuits, or the board is the old ceramic-fuse type. AS/NZS 3000 requires RCD protection on every final subcircuit when a board is replaced. If we recommend an upgrade, you'll get a separate written quote; we don't roll one into a fault-find call without telling you.
Do you carry parts on the truck?
Standard GPOs, light switches, RCBOs, common breaker amperages, junction-box accessories and a small range of light fittings - yes. Speciality items (some smart switches, designer LED drivers, three-phase RCBOs for larger homes) we'll source the same day where possible, otherwise next business day.
Same-day single-circuit diagnosis across the Illawarra.
Licensed electricians, NSW Fair Trading registered, all work to AS/NZS 3000. Honest written quotes after we look at the actual fault.