No by default: do not connect a modular PSU cable unless its compatibility with the exact power-supply model is positively documented. A plug fitting into the socket does not prove that the pins carry the same voltages. The wrong cable can damage components and create a fire or shock hazard.
This applies even when both PSUs have the same brand or wattage. Stop with the power disconnected, identify the PSU and cable, and use the manufacturer’s compatibility information. Connector shape is not proof.
1. The immediate safety rule
The component ends of common PC power cables follow defined roles, but the removable connector on the PSU side is not universally pinned across manufacturers or every family from one manufacturer. Two cables can look identical while routing a 12V, 5V, 3.3V or ground connection differently.
Corsair’s PSU cable safety explanation gives the plain answer: modular cables are PSU-specific, and even products from the same brand require a compatibility check. Seasonic likewise publishes a model-and-series compatibility guide rather than treating every cable with its name on it as interchangeable.
- Switch the PSU off and unplug it from the mains before inspecting anything.
- Do not energise an uncertain cable “just to see if it works”.
- Do not open a PSU; dangerous stored energy can remain inside.
- Do not repin, probe or repair a cable unless you are properly qualified and working to authoritative documentation.
2. Red, amber and green cable provenance
Cable provenance means knowing where the lead came from and having evidence that connects it to the exact PSU. Colour labels help you decide whether to proceed or stop; they are not a licence to infer compatibility.
| Status | Evidence | Decision |
|---|---|---|
| Green | The cable came with this exact PSU, or the manufacturer explicitly lists the cable type for the exact model/revision | Proceed only after checking the cable’s component-end purpose and condition |
| Amber | The brand or cable family is known, but the PSU revision, model suffix or chart match is incomplete | Do not connect it; ask the manufacturer or obtain a documented replacement |
| Red | Unknown loose cable, different brand, no model evidence, altered pins, damage or a match based only on appearance | Quarantine it and replace it with an approved cable |
3. Identify the PSU before the cable
Photograph the complete power-supply label while the unit is disconnected and safely accessible. Capture the manufacturer, full model, model suffix, part number, revision and serial-number area. A family name such as “RM”, “Focus” or “Straight Power” may cover several generations with different cable systems.
Then photograph both ends of the cable, its printed markings and any in-line label. Record whether the component end is intended for motherboard ATX power, CPU/EPS power, PCIe graphics, SATA power or another connection. CPU/EPS and PCIe connectors can appear related but must not be substituted for one another.
Use the model on the unit, not the online listing you remember ordering. Systems are upgraded, packaging is reused and visually similar PSUs can be mixed up. If the installed PSU label cannot be read without unsafe dismantling, stop and ask a competent technician.
4. Follow the manufacturer-and-model verification procedure
- Find the manufacturer’s current cable-compatibility chart or the exact PSU manual.
- Match the complete model and revision, not merely the brand and wattage.
- Match the cable family or official replacement part number.
- Confirm the component-end purpose and the number of connectors the manufacturer permits.
- Inspect the lead for scorched pins, looseness, damaged insulation, sharp bends or unauthorised alterations.
- If any step remains uncertain, obtain the correct lead from the PSU manufacturer or an explicitly approved supplier.
Corsair’s compatibility table, for example, separates its Type 3, Type 4 and Type 5 systems. The useful principle is not to memorise those names; it is to consult the evidence for the exact product in front of you each time.
5. Do not confuse modular leads, extensions and mains cables
A modular PSU cable runs from a socket on the PSU to a component. A decorative extension attaches to the standard component end of a known-correct PSU cable; it does not plug into the PSU itself. Extensions still need the right current capability, connector type and build quality, but they do not solve an unknown PSU-side pinout.
The detachable mains lead between the wall and PSU is another category. Standard connector families exist, but the lead still needs the correct connector, rating and condition for the equipment and local supply. Never treat “it fits” as the only electrical check.
New GPU power connectors do not make old modular ports universal. A manufacturer may sell a cable that connects approved PSU sockets to a newer GPU connector, but its product page must explicitly support your PSU family. Adaptor and GPU-side selection belong to the graphics card’s instructions, not guesswork at the PSU end.
6. What to do with an unidentified cable
Label it as unidentified and store it away from proven leads so it cannot drift back into a build. Do not sell or give it away as “probably compatible”. If the manufacturer can identify it from markings, retain that evidence with the cable; otherwise recycle or dispose of it through an appropriate electrical route.
If a wrong cable has already been powered, switch off and disconnect the system. Do not repeatedly retest it. Look for heat, smell, discolouration or component damage and seek competent assessment before applying power again.
7. Selling a modular PSU or spare computer parts
When selling a PSU, keep its confirmed original cables together and photograph what is included. Do not add uncertain loose leads to make the bundle look complete. GPUsed’s power-supply selling page explains the details needed for a quote, while the computer-component route covers a mixed set of parts.
If you need clarification before submitting, check the GPUsed FAQs. Describe missing cables and condition accurately; completeness can affect value, but an honest incomplete set is safer than an unsafe assortment.
Sources and limits
Manufacturer guidance checked on 12 September 2026. Cable families can change, and this page cannot verify a lead from appearance or photographs alone. The current compatibility document for the exact PSU remains authoritative.