MX4.2mm Power Connectors, Headers and Cable Assemblies
MX4.2mm Power Connectors, Headers and Cable Assemblies
This collection covers 4.2mm-pitch locking power-connector components and wiring commonly identified with MX4.2, 5557, 5558, 5559, 5569 and Mini-Fit-style search terms. The 32 products include single- and dual-row housings, crimp contacts, straight and right-angle PCB headers, pre-crimped leads, cable assemblies, assortments and selected PC-power formats.
These identifiers help buyers locate a mechanical format, but they do not establish original Molex manufacture, universal Mini-Fit Jr. interchangeability or a correct ATX, EPS, CPU or PCIe pinout.
Product Range
- Single-row 1×2 through 1×6 housings and PCB headers
- Dual-row 2×1 through 2×12 housings, mating plugs and terminals
- Straight and right-angle through-hole PCB header options
- 18AWG and 20AWG pre-crimped leads in selected products
- Single-ended, male-to-female and female-to-female leads
- 10cm, 20cm, 30cm and 50cm cable options in selected listings
- ATX/CPU/EPS/PCIe-shaped extensions, adapters and replacement harnesses
- Connector assortments and loose-terminal packages
Single-Row vs. Dual-Row MX4.2mm
Single-row and dual-row parts are different mating structures even when both use nominal 4.2mm contact spacing. Confirm row count, total circuits, cavity arrangement, latch position, polarization and terminal gender. A 4-position 1×4 connector is not the same as a 4-position 2×2 connector.
About 5557, 5558, 5559 and 5569 References
Listings use these numbers as format and search references for wire housings, mating plugs or PCB headers. Yoeruyo is the listed brand. Do not infer genuine manufacturer status, UL recognition or unconditional cross-brand mating from the number alone. Compare complete part numbers and dimensional drawings when replacing an existing connector.
How to Select
- Confirm nominal 4.2mm pitch and whether the assembly is single-row or dual-row.
- Choose the exact cavity layout, from 1×2–1×6 or 2×1–2×12 where offered.
- Identify housing, mating plug, loose terminal, PCB header, pre-crimped lead or finished harness.
- For PCB parts, verify straight or right-angle orientation, footprint, pin dimensions, latch clearance and board-edge relationship.
- Match the terminal to conductor cross-section and insulation diameter; selected products use 18AWG or 20AWG, but this is not universal.
- For cables, confirm end configuration, length, wire color, contact gender, pin order and quantity.
- On mixed listings, select the precise row, circuit, cable and package options.
ATX, CPU, EPS and PCIe Safety
A housing that physically resembles a PC power connector is not automatically wired for the same function. CPU/EPS, PCIe GPU and ATX connectors may use similar 4.2mm cavities while carrying different voltages, grounds, sense lines and keying. Never connect a cable based only on pin count, color or the fact that it fits. Compare the power-supply and device pinout, then test continuity end to end before energizing.
Crimping and Harness Assembly
Use the terminal specified for the selected housing and conductor. Verify conductor crimp, insulation support, bellmouth, strip length and retention-lance orientation, then perform pull and continuity tests. For loaded power circuits, evaluate contact resistance and temperature rise in the finished harness rather than relying on a connector-family headline.
Current, Voltage and Compliance Boundaries
No collection-wide 13A, 600V, AWG 14–20, copper-alloy, tin-plating, PA66, UL94 V-0, -40°C to 105°C, 30-cycle, RoHS, REACH or UL claim is supported across all 32 products. Safe capacity depends on the exact terminal, wire gauge, number of loaded circuits, ambient temperature, PCB copper, mating quality and certification evidence.
Do not use these products for safety-critical, automotive-underhood, mains, battery, server-power or high-current distribution without application-specific validation and the required approvals.
Compatibility Boundaries
MX4.2mm is not the same as MX3.0mm Micro-Fit-style, VH3.96mm, L6.2mm or other visually similar power connectors. Pitch alone cannot prove compatibility. Check housing geometry, keying, latch, terminal system and mating depth.
Frequently Asked Questions
Are these genuine Molex Mini-Fit Jr. parts?
No original-manufacturer claim is made. Mini-Fit and numbered references describe the searched format.
Will every 5557 housing mate with every 5559 header?
Not necessarily. Confirm rows, circuits, polarization, latch, contact gender and drawings.
Are all products rated for 13A per contact?
No. The usable current must be verified for the exact assembled system and operating conditions.
Can a 4-pin CPU cable be used for PCIe power?
No such substitution should be made without an exact pinout and equipment specification. A wrong cable can damage hardware.
Do all listings include housings, terminals and wires?
No. Some sell individual component types, terminals, PCB headers, pairs or finished cables. Check the selected option and package contents.
Ordering Checklist
Confirm pitch, row count, cavity layout, housing keying, latch, terminal gender, wire gauge, cable length, pinout, PCB footprint, header orientation, ratings, approvals, contents and quantity. Validate samples and temperature rise before production use.
