FIELD GUIDESource-led reference

P348 / PC internal / Connector

5 V addressable RGB header (MSI JRAINBOW)

MSI documents its three-pin five-volt JRAINBOW connector for addressable RGB lighting; it must not be treated as an ordinary four-pin twelve-volt JRGB connection.

Also called JRAINBOW 5V ARGB header 3 pin 5V digital RGB header addressable RGB motherboard

Voltage and signaling class are more important than a superficial resemblance between small lighting headers.

Look for

Find the JRAINBOW/ARGB label and 5 V marking for the exact motherboard; confirm the accessory’s intended connection before handling it.

Claim inspection dates: 2026-10-09, 2026-10-13 · Independent review pending

Image inspection / P348

See the view. Check its scope.

1 registered view for this reference. Different part examples are not automatically mates; all remain not to scale and independently unapproved.

Three contacts across four positions, with an internal gap in the inspected view. Original source-observed board-side contact-layout study; no housing specification, scale, pin functions or fit approval. (private workspace)

P348 / Source-observed physical study

5V ARGB / JRAINBOW

MSI B550-A PRO JRAINBOW1–2

Board-side plan layout, following the cited diagram orientation · Board header

Not to scale. Technical and rights review pending.

Inspect view & provenance (private workspace)
INTERNAL SYSTEMS / HEADERS

5 V addressable RGB is not the 12 V RGB standard

No. In MSI’s cited documentation, JRAINBOW is a specified 5 V addressable lighting output, distinct from 12 V JRGB. Do not infer that all three-pin motherboard headers—including fan, ARGB and other proprietary lighting variants—share voltage, pin assignment or signal type.

Conceptual role comparison: MSI JRGB / 12 V versus MSI JRAINBOW / 5 V. Wrong voltage or header can damage hardware. Not to scale, no pinout or mechanical mating dimensions.
Lighting: check the voltage first. Original qualitative role diagram; not mechanical artwork, not to scale or a wiring map. Source context S458.

Three checks before proceeding

  1. Read both hardware manuals and verify the exact 5 V addressable wiring scheme.
  2. Match the connector arrow, spacing and manufacturer-provided control cable.
  3. Do not attach to a 12 V header or unidentified fan/accessory socket.

One mistake to avoid

Matching only the number of contacts and not the marked power/signal function.

Full technical reading, sources and related identities →

Claim-specific evidence remains in the canonical record. Concept diagrams do not show any safe wiring or mechanical mating geometry.

The useful distinction

Recognize it. Then verify it.

MSI documents its three-pin five-volt JRAINBOW connector for addressable RGB lighting; it must not be treated as an ordinary four-pin twelve-volt JRGB connection. [C348A]

MSI directs users to turn off power, check model-specific manuals, and warns that mixing five-volt strips with twelve-volt JRGB damages equipment. [C348B]

B550-A PRO describes JRAINBOW1–2 as 5V WS2812B addressable-LED connections. [C348C]

The JRAINBOW source diagram leaves position 3 absent within a four-position span. [C348D]

MSI requires power-supply shutdown and disconnection from the outlet before LED-strip changes. [C348E]

Identify the documented form

Identify MSI JRAINBOW by its manual, absent position and addressable-lighting role.

  1. The JRAINBOW family is distinct from ordinary JRGB; the source drawing’s absent position is meaningful rather than a missing accidental contact. S458 · S591
  2. MSI names the supported addressable-lighting role for the cited board; that does not turn every similar small plug into that interface. S591
Documented identity facts; exact part and variant scope remains with each value
Nominal contacts3 (MSI JRAINBOW)S458Recorded source-scoped values; named examples do not describe every family variant or establish compatibility. Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval.
Positions / cavity span4 (Claim C348D); 4 (MSI B550-A PRO four-position span, position 3 absent); 4 (MSI B550-A PRO JRAINBOW1–2)S591 · S757Separate exact examples; retain each value’s source, role, axis and part scope. V142: named MSI B550-A PRO manual version 6.0 (2024/02) or explicitly identified Noctua family only. Role/recognition evidence, not generic wiring, safe mating, pinout approval, dimensions or installed-device certification. Exact named example MSI B550-A PRO JRAINBOW1–2: Device-specific5V addressable RGB header. Exact example only; no universal geometry, electrical compatibility, fabrication approval or wiring instruction. No universalARGBpitch, wire-sideview or specimenmarkings inferred.
Populated contacts3 (MSI JRAINBOW, positions 1/2/4); 3 (MSI B550-A PRO JRAINBOW1–2)S458 · S757Separate exact examples; retain each value’s source, role, axis and part scope. Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval. Exact named example MSI B550-A PRO JRAINBOW1–2: Device-specific5V addressable RGB header. Exact example only; no universal geometry, electrical compatibility, fabrication approval or wiring instruction. No universalARGBpitch, wire-sideview or specimenmarkings inferred.
Connector roleheader (MSI JRAINBOW)S458Recorded source-scoped values; named examples do not describe every family variant or establish compatibility. Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval.
Rows, pitch, dimensions, keying and view limits
Additional scoped facts; not a fabrication drawing or a mating approval
Contact rows1 (MSI B550-A PRO JRAINBOW1–2)S757Separate exact examples; retain each value’s source, role, axis and part scope. Exact named example MSI B550-A PRO JRAINBOW1–2: Device-specific5V addressable RGB header. Exact example only; no universal geometry, electrical compatibility, fabrication approval or wiring instruction. No universalARGBpitch, wire-sideview or specimenmarkings inferred.
Contact pitchNot recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
Dimensions / axisNot recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
Coupling / latchNot recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
Keying / polarizationabsent position 3 (MSI B550-A PRO JRAINBOW)S591Recorded source-scoped values; named examples do not describe every family variant or establish compatibility. V142: named MSI B550-A PRO manual version 6.0 (2024/02) or explicitly identified Noctua family only. Role/recognition evidence, not generic wiring, safe mating, pinout approval, dimensions or installed-device certification.
View conventionMSI p.41 numbered header sketch, pin1left; row positions1,2and4occupied, position3absent; do not renumber the gap. (MSI B550-A PRO JRAINBOW1–2)S757Separate exact examples; retain each value’s source, role, axis and part scope. Exact named example MSI B550-A PRO JRAINBOW1–2: Device-specific5V addressable RGB header. Exact example only; no universal geometry, electrical compatibility, fabrication approval or wiring instruction. No universalARGBpitch, wire-sideview or specimenmarkings inferred.
Contact gender / arrangementNot recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
Mountingboard (Claim C348A)S458Recorded source-scoped values; named examples do not describe every family variant or establish compatibility. Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval.
Shell / formNot recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
ManufacturerMSI (B550-A PRO JRAINBOW1-2)S591Recorded source-scoped values; named examples do not describe every family variant or establish compatibility. V142: named MSI B550-A PRO manual version 6.0 (2024/02) or explicitly identified Noctua family only. Role/recognition evidence, not generic wiring, safe mating, pinout approval, dimensions or installed-device certification.
SeriesJRAINBOW (B550-A PRO JRAINBOW1-2)S591Recorded source-scoped values; named examples do not describe every family variant or establish compatibility. V142: named MSI B550-A PRO manual version 6.0 (2024/02) or explicitly identified Noctua family only. Role/recognition evidence, not generic wiring, safe mating, pinout approval, dimensions or installed-device certification.
Exact part / implementationB550-A PRO JRAINBOW1-2 (B550-A PRO JRAINBOW1-2)S591Recorded source-scoped values; named examples do not describe every family variant or establish compatibility. V142: named MSI B550-A PRO manual version 6.0 (2024/02) or explicitly identified Noctua family only. Role/recognition evidence, not generic wiring, safe mating, pinout approval, dimensions or installed-device certification.
Recorded markingsNot recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.

Keep this limit: MSI requires power shutdown and disconnection before LED-strip changes. S591

Make the next check

Check the exact board and accessory designation, voltage and alignment instructions before handling the lighting lead.

Existing source inspection and AI review remain distinct from independent technical review. A matching form does not establish a safe connection.

Recorded variant and source limits
  • Check the exact device manual before wiring or applying power.
  • MSI MAG B550 TOMAHAWK JRAINBOW1~2: Per manual.
  • GIGABYTE B550 AORUS ELITE (AX) D_LED1/D_LED2 (comparable 5 V ARGB header, not MSI): Per manual.
  • MSI B550-A PRO JRAINBOW1–2: MSI p.41 JRAINBOW1–2 board sketch: four numbered positions, pin 1 left, position 3 absent, pin 4 right. Three contacts occupy 1, 2 and 4; the gap is not renumbered.
Report a correction to this identification or view →

Bounded facts, visible unknowns

Specifications and limits

5 V addressable RGB header (MSI JRAINBOW) facts and limitations
Documented MSI JRAINBOW formThree contacts; 5 V addressable lighting category — model check required [C348A]
Role and recognition scopeBoard header — MSI B550-A PRO JRAINBOW1–2. Original qualitative study only; no wiring or fit approval. [C348C] [C348D] [C348E]
Mechanical dimensionsOnly manufacturer-described nominal family/footprint pitch is quoted in sourced text; no measured fabrication/tolerance drawing independently approved.
Engineering pinoutSource-checked engineering profile available; independent review pending. Open engineering profile →
Verified device listNot included. Check exact device and accessory documentation.
A boundary, not an omission to guess around.

Remove PC power completely before inspecting or mating lighting headers. Check that the accessory requires five-volt addressable RGB and matches the exact motherboard’s key and polarity. Do not attach a 5 V ARGB product to a 12 V JRGB header; if the key or voltage label is unclear, stop.

Before you connect

What to check

  1. Remove PC power completely before inspecting or mating lighting headers.
  2. Check that the accessory requires five-volt addressable RGB and matches the exact motherboard’s key and polarity.
  3. Do not attach a 5 V ARGB product to a 12 V JRGB header; if the key or voltage label is unclear, stop.
Trace a supported connection class →

Pins & wiring

Pinout

Choose the exact wiring. Pin numbers follow its stated view; a schematic does not establish physical positions. Check your exact device before wiring.

What the status labels mean
Confirmed
Recorded research passes agree within this variant; this is not independent human review or hardware validation.
Single source
Only one underlying document, or one pass, supports this assignment.
Device-specific
Supported for the named equipment or wiring only. Check your device’s manual.
Unverified
Missing or conflicting evidence. Do not wire from this row.
Not connected
The source explicitly says NC, no contact or no pin for this wiring.
Wiring variant

MSI MAG B550 TOMAHAWK JRAINBOW1~2

Device-specific wiring. Check your device’s manual before connecting or applying power.

View and evidence limits

Per manual.

  • P348 MSI JRAINBOW — **Agree**: 1 +5 V, 2 data, position 3 absent, 4 ground — Different MSI board manuals, plus GIGABYTE D_LED in A. Preserve the missing position instead of renumbering the three contacts 1-3.
  • MSI: up to 75 WS2812B LEDs, max 3 A at 5 V.
  • Only one MSI manual was read. The mating 3-wire plug numbering is not separately documented.
5 V addressable RGB header (MSI JRAINBOW) engineering referencePer manual.SCHEMATIC · physical positions unconfirmedNot to scale · check the named wiring and device manual1: +5V (device_specific)12: Data (device_specific)23: No Pin (not_connected)34: Ground (device_specific)4powergrounddataConfigshieldNCUnknown
Schematic only · physical contact positions unconfirmed. Original drawing · not to scale. Scroll sideways if needed.
MSI MAG B550 TOMAHAWK JRAINBOW1~2 — source-scoped contact map
PinSignalWhat it doesStatus
1+5VPower connection (+5V). Check the specified supply.Device-specific
Sources
2DataSignal conductor. Pair, polarity and direction follow this named wiring.Device-specific
Sources
3No PinNot connected or absent in this named wiring.Not connected
Sources
4GroundGround reference and return.Device-specific
Sources
Sources (1)

GIGABYTE B550 AORUS ELITE (AX) D_LED1/D_LED2 (comparable 5 V ARGB header, not MSI)

Device-specific wiring. Check your device’s manual before connecting or applying power.

View and evidence limits

Per manual.

  • P348 MSI JRAINBOW — **Agree**: 1 +5 V, 2 data, position 3 absent, 4 ground — Different MSI board manuals, plus GIGABYTE D_LED in A. Preserve the missing position instead of renumbering the three contacts 1-3.
  • GIGABYTE: max 5 A at 5 V, up to 1000 LEDs.
  • Only one MSI manual was read. The mating 3-wire plug numbering is not separately documented.
5 V addressable RGB header (MSI JRAINBOW) engineering referencePer manual.SCHEMATIC · physical positions unconfirmedNot to scale · check the named wiring and device manual1: V (5V) (device_specific)12: Data (device_specific)23: No Pin (not_connected)34: GND (device_specific)4powergrounddataConfigshieldNCUnknown
Schematic only · physical contact positions unconfirmed. Original drawing · not to scale. Scroll sideways if needed.
GIGABYTE B550 AORUS ELITE (AX) D_LED1/D_LED2 (comparable 5 V ARGB header, not MSI) — source-scoped contact map
PinSignalWhat it doesStatus
1V (5V)Power connection (V (5V)). Check the specified supply.Device-specific
Sources
2DataSignal conductor. Pair, polarity and direction follow this named wiring.Device-specific
Sources
3No PinNot connected or absent in this named wiring.Not connected
Sources
4GNDGround reference and return.Device-specific
Sources
Sources (1)

MSI B550-A PRO JRAINBOW1–2

Device-specific wiring. Check your device’s manual before connecting or applying power.

View and evidence limits

MSI p.41 JRAINBOW1–2 board sketch: four numbered positions, pin 1 left, position 3 absent, pin 4 right. Three contacts occupy 1, 2 and 4; the gap is not renumbered.

  • P348 MSI JRAINBOW — **Agree**: 1 +5 V, 2 data, position 3 absent, 4 ground — Different MSI board manuals, plus GIGABYTE D_LED in A. Preserve the missing position instead of renumbering the three contacts 1-3.
  • MSI describes WS2812B 5V/Data/Ground strips and a 3 A at 5 V limit. Its warning says a 5 V strip can be damaged on JRGB.
  • Other three-contact arrangements, detailed data waveforms, cable-rear numbering and arbitrary LED compatibility are unverified.
5 V addressable RGB header (MSI JRAINBOW) engineering referenceMSI p.41 JRAINBOW1–2 board sketch: four numbered positions, pin 1 left, position 3 absent, pin 4 right. Three contacts occupy 1, 2 and 4; the gap is not renumbered.SCHEMATIC · physical positions unconfirmedNot to scale · check the named wiring and device manual1: +5V (device_specific)12: Data (device_specific)23: No Pin (not_connected)34: Ground (device_specific)4powergrounddataConfigshieldNCUnknown
Schematic only · physical contact positions unconfirmed. Original drawing · not to scale. Scroll sideways if needed.
MSI B550-A PRO JRAINBOW1–2 — source-scoped contact map
PinSignalWhat it doesStatus
1+5VPower connection (+5V). Check the specified supply.Device-specific
Sources
2DataSignal conductor. Pair, polarity and direction follow this named wiring.Device-specific
Sources
3No PinNot connected or absent in this named wiring.Not connected
Sources
4GroundGround reference and return.Device-specific
Sources
Sources (1)

Important boundary

This reference establishes only the specific manufacturer-documented family and example noted in the sources. It does not verify an arbitrary mating pair, cable orientation, electrical rating or device combination. Stop and consult original documents for the exact products.

Source-scoped V142 recognition check

MSI B550-A PRO JRAINBOW1–2. Three contacts across four positions, with an internal gap in the inspected view. Addressable lighting is a different documented interface. Verify the exact 5V addressable header and LED/controller documentation. Still unresolved: Other vendors’ three-pin arrangements, signal implementations and assembled-device approval. See the internal-header field reference for source revision, observation limits and the comparison.

Your next step

Move from the form to the requirement.

The source trail

Evidence for this page

AI-assisted inspection is not independent engineering review. Source scope and access limitations are disclosed below. Procedural checklists are editorial requirements, not hardware measurements.

Back to first citation ↑
C348ASource checked · pending review

MSI identifies JRAINBOW as a five-volt, three-pin addressable-RGB motherboard header.

MSI · Installation method for JRGB and JRAINBOW connectors on MSI motherboards ↗

Locator: JRGB connector; JRAINBOW connector; warning on voltage mismatch; motherboard manual check
Access: public page. Other LED headers and proprietary variants exist. No universal header assignment or exact LED current assumption.

S458: full source recordInspect review dependencies → (private workspace)

Claim scope: Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval.. Next review due 2027-01-07.

Back to first citation ↑
C348BSource checked · pending review

MSI directs users to turn off power, check model-specific manuals, and warns that mixing five-volt strips with twelve-volt JRGB damages equipment.

MSI · Installation method for JRGB and JRAINBOW connectors on MSI motherboards ↗

Locator: JRGB connector; JRAINBOW connector; warning on voltage mismatch; motherboard manual check
Access: public page. Other LED headers and proprietary variants exist. No universal header assignment or exact LED current assumption.

S458: full source recordInspect review dependencies → (private workspace)

Claim scope: Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval.. Next review due 2027-01-07.

Back to first citation ↑
C348CSource checked · pending review

B550-A PRO describes JRAINBOW1–2 as 5V WS2812B addressable-LED connections.

MSI · MSI B550-A PRO User Guide, version 6.0 (2024/02) ↗

Locator: PDF pp.33, 36–38, 40–41; p.59 / printed ix revision history. Source diagrams visually inspected at zero-based pages 32,35,36,37,39,40,58.
Access: public pdf text. Observed document is not a real-hardware inspection, installed-device approval, wiring guide, current revision guarantee or manufacturing specification.

S591: full source recordInspect review dependencies → (private workspace)

Claim scope: V142: named MSI B550-A PRO manual version 6.0 (2024/02) or explicitly identified Noctua family only. Role/recognition evidence, not generic wiring, safe mating, pinout approval, dimensions or installed-device certification.. Next review due 2027-01-11.

Back to first citation ↑
C348DSource checked · pending review

The JRAINBOW source diagram leaves position 3 absent within a four-position span.

MSI · MSI B550-A PRO User Guide, version 6.0 (2024/02) ↗

Locator: PDF pp.33, 36–38, 40–41; p.59 / printed ix revision history. Source diagrams visually inspected at zero-based pages 32,35,36,37,39,40,58.
Access: public pdf text. Observed document is not a real-hardware inspection, installed-device approval, wiring guide, current revision guarantee or manufacturing specification.

S591: full source recordInspect review dependencies → (private workspace)

Claim scope: V142: named MSI B550-A PRO manual version 6.0 (2024/02) or explicitly identified Noctua family only. Role/recognition evidence, not generic wiring, safe mating, pinout approval, dimensions or installed-device certification.. Next review due 2027-01-11.

Back to first citation ↑
C348ESource checked · pending review

MSI requires power-supply shutdown and disconnection from the outlet before LED-strip changes.

MSI · MSI B550-A PRO User Guide, version 6.0 (2024/02) ↗

Locator: PDF pp.33, 36–38, 40–41; p.59 / printed ix revision history. Source diagrams visually inspected at zero-based pages 32,35,36,37,39,40,58.
Access: public pdf text. Observed document is not a real-hardware inspection, installed-device approval, wiring guide, current revision guarantee or manufacturing specification.

S591: full source recordInspect review dependencies → (private workspace)

Claim scope: V142: named MSI B550-A PRO manual version 6.0 (2024/02) or explicitly identified Noctua family only. Role/recognition evidence, not generic wiring, safe mating, pinout approval, dimensions or installed-device certification.. Next review due 2027-01-11.

Suggest a correction to this field note →

Put this field note to work.

Add to discovery trayRecord an unsaved candidate (private workspace)

Candidate selection does not confirm the identity or capabilities of your physical item.

Evidence behind this page

Scope first. Source second. Approval separate.

2 linked sources · 5 scoped claims · 0 sources with inspection/access flags.

Page scope: evidence_first_v103_pc_and_jst

Assessment 2026-10-22 · earliest scheduled source review 2027-01-07. This is a recorded-date assessment, not a live source check. Page-level independent review is not established by this panel.

Inspect 2 source scopes, access limits and dates

S458 · Installation method for JRGB and JRAINBOW connectors on MSI motherboards

MSI · Unclassified publisher domain · inspected 2026-10-09 · due 2027-01-07

Within inspection window

Scoped support: Manufacturer-specific 12V 4-pin JRGB and 5V 3-pin JRAINBOW distinction, power-off and damage warning.

Not established / limitations: Other LED headers and proprietary variants exist. No universal header assignment or exact LED current assumption.

Locator: JRGB connector; JRAINBOW connector; warning on voltage mismatch; motherboard manual check

S591 · MSI B550-A PRO User Guide, version 6.0 (2024/02)

MSI · Unclassified publisher domain · inspected 2026-10-13 · due 2027-01-11

Within inspection window

Scoped support: Named B550-A PRO board header identities, diagram-level contact/key arrangements, control modes and RGB mismatch warnings.

Not established / limitations: Observed document is not a real-hardware inspection, installed-device approval, wiring guide, current revision guarantee or manufacturing specification.

Locator: PDF pp.33, 36–38, 40–41; p.59 / printed ix revision history. Source diagrams visually inspected at zero-based pages 32,35,36,37,39,40,58.

Trace 5 claims to their source records

C348A · P348

MSI identifies JRAINBOW as a five-volt, three-pin addressable-RGB motherboard header.

Claim scope: Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval.

Source links: S458 · Evidence trail → (private workspace)

C348B · P348

MSI directs users to turn off power, check model-specific manuals, and warns that mixing five-volt strips with twelve-volt JRGB damages equipment.

Claim scope: Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval.

Source links: S458 · Evidence trail → (private workspace)

C348C · P348

B550-A PRO describes JRAINBOW1–2 as 5V WS2812B addressable-LED connections.

Claim scope: V142: named MSI B550-A PRO manual version 6.0 (2024/02) or explicitly identified Noctua family only. Role/recognition evidence, not generic wiring, safe mating, pinout approval, dimensions or installed-device certification.

Source links: S591 · Evidence trail → (private workspace)

C348D · P348

The JRAINBOW source diagram leaves position 3 absent within a four-position span.

Claim scope: V142: named MSI B550-A PRO manual version 6.0 (2024/02) or explicitly identified Noctua family only. Role/recognition evidence, not generic wiring, safe mating, pinout approval, dimensions or installed-device certification.

Source links: S591 · Evidence trail → (private workspace)

C348E · P348

MSI requires power-supply shutdown and disconnection from the outlet before LED-strip changes.

Claim scope: V142: named MSI B550-A PRO manual version 6.0 (2024/02) or explicitly identified Noctua family only. Role/recognition evidence, not generic wiring, safe mating, pinout approval, dimensions or installed-device certification.

Source links: S591 · Evidence trail → (private workspace)

Prepare this page for review → (private workspace)Read the evidence method →

Recorded evidence only. An inspection date, publisher label, source link or generated packet is not independent technical review, hardware testing, fabrication approval or a compatibility verdict.