Fault-finding
The picture flickers or rolls
Electrical interference or a sagging power supply causes most flicker. Slow horizontal bands rolling up the image mean the video cable is picking up mains interference, usually because the two share trunking. Flicker that comes with visible dimming points instead at a supply that cannot hold voltage once the camera loads it.
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Step 1: trace the cable route
Find where the video run travels beside mains wiring. Sharing plaza trunking or riding along a ceiling with power cable for metres at a stretch induces exactly this rolling-band interference; crossing mains at right angles does not. Re-routing the affected section fixes it permanently, and it is a wiring-discipline fault, not an equipment one — no new camera will out-run a bad route.
Step 2: measure the supply under load
An adaptor can read a clean 12 V unloaded and sag the moment the camera works hard — infra-red on, or a cold morning start. Measure at the camera end while the symptom is showing. A supply that droops under load produces flicker, dimming and random restarts, and swapping in a properly rated unit is one of the cheapest permanent fixes in CCTV.
Step 3: check the anti-flicker setting
Fluorescent tubes and cheap LED batons flick on and off with the mains cycle, and a camera shutter out of step with that cycle records the pulsing as flicker or banding. Recorders and cameras carry an anti-flicker or 50 Hz setting for precisely this. If the flicker only appears under certain indoor lights, correct the setting before touching any wiring — it is a one-line menu change.
What makes a CCTV picture flicker?
Could the camera itself be faulty?
Possible, but down the list. Swap it onto another channel and another supply; if the flicker follows the camera, it is the camera. In most tests it stays with the cable run or the adaptor.
It flickers when the UPS or generator kicks in — related?
Very likely. Backup power is electrically noisier than the mains, and a marginal camera supply shows it first. A cleaner supply on the camera side, or a better-quality UPS, settles it.
Rather have it done?
Security camera repair covers black screens, recorders that stopped writing, lost phone access after an internet change, and footage that will not play back. Most faults trace to power, connectors or settings rather than a dead camera. Callout in Islamabad or Rawalpindi starts at PKR 3,000, with the full fix priced before any work.
Security camera repair in Islamabad — prices and scope