Answer what you can see below. This ranks the likely causes, gives you one safe next check, and tells you clearly when to stop and call a licensed electrician.
Stop and call a licensed electrician or emergency services now if there's smoke, sparks, a burning smell, heat, shock, or water near the problem. Otherwise it's safe to answer the questions below.
What can you see?
Diagnosis
Example result — change the answers on the left and the ranking updates for your situation.
Most likely cause
Protection is spent or degraded — the unit keeps delivering power but is no longer clamping surges
Ranked by fit to your answers
1
Protection is spent or degraded — the unit keeps delivering power but is no longer clamping surges
90
SAFE NEXT CHECKTreat it as an unprotected power strip and replace it; it will keep delivering power but is no longer clamping surges. Choose a replacement with a status indicator.
Where to stop. Swapping a plug-in surge strip is homeowner-safe. If the "Grounded" light is off, the receptacle itself may be ungrounded or miswired — confirm with a plug-in tester, and because correcting house wiring means live conductors, if a tester shows an open ground have a licensed electrician verify the outlet. This is general information, not a quote and not a substitute for a licensed electrician.
Rule trace — why this ranking
The protection indicator has gone out — on most units this is the explicit end-of-life signal that the MOVs have degraded past threshold. +90
What to do next
Try the safe next check above. If it doesn't resolve the problem — or if sorting it out would mean opening a panel, touching wiring, or anything past a simple visual check — stop and call a licensed electrician. Don't replace parts on a guess.
Confirm it with
Plug-in outlet/GFCI tester
If a part needs replacing, likely
Replacement surge protector (with status indicator)
Not your exact situation? Change any answer above and the ranking updates — or try a related situation below.
source-governed · verified 2026-06-20
Sources
standard UL 1449 — Standard for Surge Protective Devices · verified 2026-06-20
Named standards and manufacturer guidance, re-verified on a freshness schedule. When a source cannot be re-verified, the dependent rule is suppressed rather than asserted.
My surge protector still powers my devices — doesn't that mean it's protecting them?
No. A surge protector keeps passing power long after its protection components are spent. Powered-on tells you the outlet portion works, not that surges are still being clamped — that's what the protection indicator is for.
The protection light went out. Is the strip broken?
The strip usually still delivers power, but on most units a dark protection light means the internal MOVs have degraded past their threshold and the unit is no longer clamping surges. Treat it as an unprotected power strip and replace it.
Does the 'grounded' light matter?
Yes. Surge energy is diverted to ground, so an ungrounded or miswired outlet undercuts protection even when the MOVs are fine. If the grounded light is off, confirm the receptacle with a plug-in tester.
Electrical Fault Check provides general diagnostic information only. It is not professional advice, not a quote, and not a substitute for a licensed electrician. Do not work on live wiring. If you see smoke, sparks, burning smell, heat, shock, water exposure, or repeated tripping, stop using the circuit and contact a licensed electrician or emergency services as appropriate.