The short answer
Isolate power and diagnose the circuit before cutting. Confirm that the fault stays with one local section after supply, feed, polarity, controller, voltage drop and joints have been checked. Then identify the exact strip SKU and obtain its designated cut points, pad layout, width, voltage, colour specification, power, coating, connector or solder method, maximum run and resealing instructions. Replace only at permitted cut points with a documented matching section and approved connection method. If those facts are unavailable—currently including the public Glowfy SW24-15 cut interval and repair accessory—replace the documented run or ask the supplier for instructions rather than improvising a local repair.
1. Make the installation safe and preserve the evidence
Switch off and isolate the relevant supply before touching the strip, joints or conductors. Confirm the circuit is de-energised using an appropriate method. Fixed wiring and mains work belong to a competent person. Stop for burnt insulation, arcing, melted connectors, water inside an enclosure or repeated protective-device operation; those conditions require a wider safety investigation.
Photograph the failed area, both nearest joints, feed point, controller and power-supply labels before disturbing anything. Mark the start and end of the dark section and note whether it is completely off, dim, intermittent, a different colour or affected only on one RGB channel. Record whether pressure, movement, temperature or dimming changes the symptom without repeatedly flexing a damaged strip.
Keep offcuts, failed joints and labels. If a warranty or supplier claim may apply, ask for direction before cutting. A local repair can remove the evidence needed to distinguish product failure from installation damage.
2. Prove the fault is local before planning a splice
Check the complete path from supply to load. Verify the exact supply output, branch protection, controller output, polarity, feed connections and conductor condition. Compare the affected run with a known-good branch only using a safe, documented method. Do not probe adjacent exposed pads while live or short outputs to see what happens.
Measure voltage at the supply and at documented accessible points under load where the product and test method permit. A strip that dims progressively with distance, or recovers when fed correctly, points to voltage drop or feed design rather than one failed segment. A whole downstream length going dark after a joint points first to that connection or conductor.
For colour-changing strip, test whether the fault follows a channel or controller output. A local red-channel loss can look like a failed section while the common supply remains present. Record the controller mode and wiring before moving any channel. If the symptom cannot be localised without unsafe access, replace or return the assembly instead of cutting speculatively.
| Symptom | Check before cutting | Likely decision gate |
|---|---|---|
| Whole run off | Supply, protection, controller, feed and polarity | Not a local-section repair until upstream cause is excluded |
| Far end gradually dim | Under-load voltage and feed/run design | Correct voltage drop or power injection |
| Everything after one joint off | Joint, conductor and pad contact | Repair the documented joint if approved |
| One short section dark | Local damage plus adjacent segment behaviour | Consider section replacement only with exact cut data |
| One RGB colour missing | Channel wiring and controller output | Diagnose channel compatibility first |
| Intermittent when moved | Cracked circuit, joint or strain damage | Isolate; replace or repair only to manufacturer method |
3. Identify the exact strip and replacement section
Record manufacturer, full SKU and revision, batch or date code, rated voltage, power per metre, colour temperature or RGB channel order, LED density, strip width, pad pitch, segment length, coating or encapsulation, IP construction and conductor markings. The replacement must match the electrical and mechanical system, not merely light in roughly the same colour.
Compare printed markings and manufacturer documents for the existing and replacement pieces. For white strip, match the specified colour temperature and, where the project requires it, binning or colour-tolerance evidence. For RGB or tunable white, match the common-anode or common-cathode arrangement and the exact pad order. Never infer channel order from wire colours alone.
Use traceable stock. An unlabelled offcut may have a different voltage, power, LED pitch, colour bin or coating even when its width looks right. If identity cannot be established, the repair cannot be documented as compatible.
4. Obtain the product-specific cut and connector rules
Find the designated cut symbol and permitted cut interval in the current instructions for the exact strip. Confirm which copper pads remain on each side of the cut and whether the chosen connector must approach from a particular side. Philips' MASTER/CorePro guide shows that its families use different cut sizes and that the correct cut position depends on the connector assembly side; that detail must not be transferred to another strip.
Confirm whether field reconnection is permitted and which connector, soldering process, heat limit, support and strain relief are specified. A connector must match strip width, pad count, coating and current. The Philips guide also applies family-specific connector load and maximum-length limits, illustrating why a generic clip is not automatically suitable.
For an IP-coated or encapsulated strip, obtain the exact method for exposing pads and restoring environmental protection. An IP rating for the original product does not automatically remain after cutting. The repaired joint, end seal, cable entry, enclosure and mounting details each need their own documented protection.
5. Treat the current SW24-15 listing as identity data, not a repair method
The current Glowfy page identifies SW24-15 as SKU GF-STRIP-CW-24V-5M, 24 V, 15 W/m, 6500 K, IP65, 5 m Ă— 12 mm and a 5 m purchase unit. Those fields are useful for identifying the delivered variant and assessing a proposed replacement section.
The public page does not state cut interval, copper-pad layout, LED density, permitted solder process, compatible repair connector, maximum post-connector current or resealing method. Glowfy's two listed 0.5 mm² cable products are installation conductors, not evidence of a strip repair accessory. Request the current SKU documentation before cutting.
Do not copy the 5 cm or 10 cm Philips family cut sizes, the Philips connector references or their 2 A/48 W series limit to SW24-15. They describe the named Philips systems only. The professional conclusion when SW24-15 repair data is missing is a hold point, not an invented dimension.
6. Use a repair-or-replace decision checklist
A local repair is reasonable only when every required field can be closed with product-specific evidence and the installation remains serviceable. If one material field is unknown, replace the documented run or seek manufacturer direction. The cost of a larger replacement is usually lower than a hidden unsupported joint failing after the sign is closed.
Prepare the replacement section and connection on a suitable work surface according to the instructions. Isolate before every cut or connection. Support the strip so solder pads or connectors do not carry cable tension, maintain permitted bend radius and spacing, and keep the joint accessible where the design requires service.
Do not bridge a damaged section with a wire while leaving burnt or delaminated material in place. Remove only at documented cut points, and do not reduce creepage, insulation, strain relief or environmental protection to make a generic connector fit.
| Decision field | Evidence needed | Replace or hold if |
|---|---|---|
| Fault location | Upstream, joint and voltage-drop causes excluded | Cause remains uncertain |
| Strip identity | Exact SKU/revision and traceable replacement | Existing or replacement section is unlabelled |
| Electrical match | Voltage, power, channel order and polarity match | Any electrical field differs or is unknown |
| Mechanical match | Width, pad count/pitch, cut interval and coating match | Connector or pads do not align exactly |
| Approved method | Current connector/solder and support instructions | Only a generic online method is available |
| Environmental restoration | Documented seal/end treatment and cure | Required IP protection cannot be restored |
| Acceptance test | Safe under-load method and project criteria | No access or criteria for post-repair verification |
7. Test the repaired run before closing the sign
Inspect the isolated joint for correct polarity and channel order, full pad contact, insulation, strain relief, support and restored coating or enclosure seal. Check that no copper, clipped wire or conductive debris can bridge adjacent pads. Verify that the repaired run still respects maximum length and feed rules.
Energise using the product's permitted commissioning method. Record supply voltage and any required under-load measurements at defined points, then observe the repaired section and adjacent segments at the relevant operating levels. Check for stable light, colour consistency, abnormal heat, smell, sound, arcing or controller faults. Stop and isolate on any abnormal condition.
Allow for the specified curing or sealing time before exposure. Photograph the completed joint and its location, update the wiring or service drawing, and record the replacement section batch and connection method. A passed bench observation does not override missing product instructions.
8. Worked example: one dark area in a 5 m 24 V IP65 run
A sign shop finds a short dark area in a five-metre run labelled GF-STRIP-CW-24V-5M. The supply and upstream strip remain lit. The fitter isolates the circuit, photographs the run and labels, checks the feed and nearest joints, and records under-load voltage only at safe accessible points using the approved test method. The symptom remains local rather than progressively dimming along the run.
The replacement proposal matches the public 24 V, 15 W/m, 6500 K, IP65 and 12 mm fields, but the available page does not provide the cut interval, pad layout, repair connector or resealing process. The fitter therefore does not cut at a visually convenient line or fit a generic 12 mm clip.
The job is held while Glowfy supplies the current SKU instructions or directs replacement of the run. If the exact document later permits a sectional repair, the fitter records the designated cuts, verified replacement section, approved joint, IP restoration and under-load acceptance. If it does not, the five-metre run is replaced and the failed material retained for the supplier decision.
Frequently asked questions
Can I cut out only the failed part of an LED strip?
Only if the exact strip instructions permit field cutting and reconnection, the fault has been isolated to that section, and you have verified cut points, pad layout, replacement compatibility, connection method and environmental restoration.
Is matching the voltage and strip width enough?
No. Also match power, segment and pad geometry, LED or channel arrangement, colour specification, coating, connector or solder method, run limits and sealing requirements.
Can I use a generic clip connector on an IP65 strip?
Not without product-specific evidence. The connector must match width, pad count, coating and load, and the instructions must explain how the cut joint regains the required environmental protection.
Should I repair a dark strip section that may be under warranty?
Preserve photographs, labels, failed parts and the unmodified evidence, then ask the supplier before cutting. A repair can affect the evidence needed for a warranty or failure assessment.
Technical references
Use the current datasheet for the exact product you install. These manufacturer and standards resources explain the general principles.
Confirm the repair evidence before cutting
Share the strip label, failed-area photographs, proposed replacement section and exact joint instructions so Glowfy can help identify missing compatibility checks.