FIELD GUIDESource-led reference
Port & Cable

P345 / PC internal / Connector

Internal USB 2.0 dual-port header — keyed 2×5, pin 9

Intel’s Thin Mini-ITX front-panel USB 2.0 example uses a dual-row 2×5 arrangement at 2.54 mm nominal pitch with position 9 absent as a key.

Also called 9-pin USB 2.0 header USB 2 front panel header internal 2x5 USB2 front USB2 header

A keyed header silhouette is not enough: Intel also documents a separate internal variant keyed at two positions.

Look for

Identify the missing key position using the exact board diagram; distinguish this front-panel header from USB 3.0 19-pin and USB Type-C Key-A headers.

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

Internal USB 2.0 dual-port header — keyed 2×5, pin 9: three-quarter view. Computer-generated illustration, not a photograph.

Three-quarter view Computer-generated illustration with prior AI visual review. Not a photograph, measurement or compatibility check. Independent technical and rights review pending.

Internal USB 2.0 dual-port header — keyed 2×5, pin 9: mating face. Computer-generated illustration, not a photograph.

Mating face Computer-generated illustration with prior AI visual review. Not a photograph, measurement or compatibility check. Independent technical and rights review pending.

Internal USB 2.0 dual-port header — keyed 2×5, pin 9: fitted in place. Computer-generated illustration, not a photograph.

Fitted in place Computer-generated illustration with prior AI visual review. Not a photograph, measurement or compatibility check. Independent technical and rights review pending.

Internal USB 2.0 dual-port header — keyed 2×5, pin 9: original recognition drawing, not to scale.

Recognition drawing Original schematic, not to scale. Drawing review pending.

Image inspection / P345

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.

Two rows with the absent position at a row end in this source view. Original source-observed board-side contact-layout study; no housing specification, scale, pin functions or fit approval. (private workspace)

P345 / Source-observed physical study

USB 2.0 / JUSB1–2

MSI B550-A PRO JUSB1–2

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

The missing ninth pin identifies one Intel USB 2.0 header example

No. Intel’s Thin Mini-ITX design guide documents an example dual-port USB 2.0 header with position 9 absent. Another Intel front-panel audio example uses a different absent position. Neither example universalizes all motherboard layouts or allows an unknown keyed header to be wired by eye.

Conceptual role comparison: USB 2.0 front-panel example versus HD Audio front-panel example. Different signals and manufacturer-specific assignments; never force. Not to scale, no pinout or mechanical mating dimensions.
Look-alike motherboard keys. Original qualitative role diagram; not mechanical artwork, not to scale or a wiring map. Source context S456 · S457.

Three checks before proceeding

  1. Read the motherboard’s USB2/JUSB or front-panel label and pin-key diagram.
  2. Confirm connector orientation and chassis-cable part compatibility.
  3. If labels or cable keys disagree, stop and obtain exact service instructions.

One mistake to avoid

Plugging a similar 9-position front-panel cable into an unverified motherboard header.

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.

Intel’s Thin Mini-ITX front-panel USB 2.0 example uses a dual-row 2×5 arrangement at 2.54 mm nominal pitch with position 9 absent as a key. [C345A]

The same guide separately documents a dual internal USB 2.0 variant keyed at both positions 9 and 10; the keying must be identified explicitly. [C345B]

B550-A PRO assigns JUSB1–2 to front-panel USB 2.0 ports, separately from JUSB3 and JUSB4. [C345C]

Its JUSB1–2 table distinguishes absent position 9 from present but unconnected position 10. [C345D]

MSI warns that incorrect USB-header power/ground connections can damage equipment. [C345E]

PC internals · a documented check

Is this keyed motherboard header USB 2.0 or front-panel audio?

Read the board label and its own diagram. In the MSI B550-A PRO manual, JUSB1–2 serves USB 2.0 and JAUD1 serves front audio. An absent contact and an unconnected contact are different observations. C345C · C345D · C346C · C346D

What the documentation establishes—and what still needs checking
CheckDocumented distinctionBoundary
USB exampleB550-A PRO JUSB1–2: position 9 absent; position 10 present but unconnected. C345DDo not treat every unused position as a missing physical pin.
Audio exampleB550-A PRO JAUD1: position 8 absent; position 4 unconnected. C346D · C346EThe audio header is not an alternative USB port.
Platform variationThe cited Intel audio examples use different pitches: Thin Mini-ITX 2.54 mm; NUC 9 2.0 mm. C346A · C346BThe same nominal 2×5 arrangement is not a universal mating-size rule.

Check these next

  1. Match the motherboard’s exact model and printed header name to its manual.
  2. Identify the chassis cable designation separately from the board header.
  3. Use the manual’s numbered viewpoint; do not mirror a generic pin map or force a blocked cavity.

Keep this limit: MSI warns that incorrect USB-header power/ground connections can damage equipment. This comparison is not a wire-assignment instruction. C345E

Source-scoped identification facts

Each value retains its exact example, role and measurement axis. Facts from different parts must not be combined into an invented component.

Documented examples; not a mating drawing or compatibility approval
Contact rows2 (Source-described array; C345A); 2 (B550-A PRO:JUSB1/JUSB2)S456 · S757Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval. B550-A PRO:JUSB1/JUSB2. Documented role: PCB header. IntelThinMiniITXRev1.2p.24USB2.0separately states2.54mmpitch;thatoldnominalscopeisretained,notremeasuredhere.; No board label,partmanufacturerorUSB/audiointerchangeabilityinferredfromsame2x5outline.
Contact pitch2.54 mm Source-described pitch / centerline (Claim C345A)S456Recorded 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.
Connector rolePCB header (B550-A PRO:JUSB1/JUSB2)S757Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. B550-A PRO:JUSB1/JUSB2. Documented role: PCB header. IntelThinMiniITXRev1.2p.24USB2.0separately states2.54mmpitch;thatoldnominalscopeisretained,notremeasuredhere.; No board label,partmanufacturerorUSB/audiointerchangeabilityinferredfromsame2x5outline.
Keying / polarization10positionoutlinewithpin9absent;pin10NCnotmissing (B550-A PRO:JUSB1/JUSB2)S757Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. B550-A PRO:JUSB1/JUSB2. Documented role: PCB header. IntelThinMiniITXRev1.2p.24USB2.0separately states2.54mmpitch;thatoldnominalscopeisretained,notremeasuredhere.; No board label,partmanufacturerorUSB/audiointerchangeabilityinferredfromsame2x5outline.
ManufacturerMSI (B550-A PRO:JUSB1/JUSB2)S757Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. B550-A PRO:JUSB1/JUSB2. Documented role: PCB header. IntelThinMiniITXRev1.2p.24USB2.0separately states2.54mmpitch;thatoldnominalscopeisretained,notremeasuredhere.; No board label,partmanufacturerorUSB/audiointerchangeabilityinferredfromsame2x5outline.
SeriesB550-A PRO (B550-A PRO:JUSB1/JUSB2)S757Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. B550-A PRO:JUSB1/JUSB2. Documented role: PCB header. IntelThinMiniITXRev1.2p.24USB2.0separately states2.54mmpitch;thatoldnominalscopeisretained,notremeasuredhere.; No board label,partmanufacturerorUSB/audiointerchangeabilityinferredfromsame2x5outline.
Exact part / implementationB550-A PRO:JUSB1/JUSB2 (B550-A PRO:JUSB1/JUSB2)S757Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. B550-A PRO:JUSB1/JUSB2. Documented role: PCB header. IntelThinMiniITXRev1.2p.24USB2.0separately states2.54mmpitch;thatoldnominalscopeisretained,notremeasuredhere.; No board label,partmanufacturerorUSB/audiointerchangeabilityinferredfromsame2x5outline.
View conventionPublished board-side connector diagram:odd1–9onlowerrow,even2–10onupperrow,lefttoright. Cablewire-sideisnotshown. (B550-A PRO:JUSB1/JUSB2)S757Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. B550-A PRO:JUSB1/JUSB2. Documented role: PCB header. IntelThinMiniITXRev1.2p.24USB2.0separately states2.54mmpitch;thatoldnominalscopeisretained,notremeasuredhere.; No board label,partmanufacturerorUSB/audiointerchangeabilityinferredfromsame2x5outline.

Not recorded: Nominal contacts, Positions / cavity span, Populated contacts, Dimensions / axis, Contact gender / arrangement, Mounting, Coupling / latch, Shell / form, Recorded markings. Unknown fields stay unknown; illustrations supply no measurements or pin assignments.

Recorded variant and source limits
  • Check the exact device manual before wiring or applying power.
  • Intel Front Panel I/O Design Guide 2x5 USB header: Per Table 3-1.
  • MSI MAG B550 TOMAHAWK JUSB1~2: Per manual.
  • GIGABYTE B550 AORUS ELITE (AX) F_USB1/F_USB2: Per manual.
  • Intel Thin Mini-ITX front-panel USB 2.0, pin-9 key: Figure 2-8 motherboard-header illustration: key lower right, No Connect directly above it, with two separately labeled USB-port rows. Table 2-9 supplies numbers; cable wire-side orientation is not labeled.
  • MSI B550-A PRO JUSB1–2: MSI p.37 board drawing: 2 upper left, 10 upper right, 1 lower left, absent 9 lower right. Cable rear not established.
Report a correction to these facts →

Bounded facts, visible unknowns

Specifications and limits

Internal USB 2.0 dual-port header — keyed 2×5, pin 9 facts and limitations
Source-scoped example2×5 footprint, one absent key at pin 9, nominal 2.54 mm (Intel Thin Mini-ITX) [C345A]
Role and recognition scopeBoard header — MSI B550-A PRO JUSB1–2. Original qualitative study only; no wiring or fit approval. [C345C] [C345D] [C345E]
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.

Disconnect all power and locate the board’s labeled USB2 header diagram, not an online generic pinout. Compare both the keyed position and pitch before considering a cable end; never rotate a mismatched plug to force it. Check the intended front-panel USB device and its cable documentation; do not touch exposed power contacts.

Before you connect

What to check

  1. Disconnect all power and locate the board’s labeled USB2 header diagram, not an online generic pinout.
  2. Compare both the keyed position and pitch before considering a cable end; never rotate a mismatched plug to force it.
  3. Check the intended front-panel USB device and its cable documentation; do not touch exposed power contacts.
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

Intel Front Panel I/O Design Guide 2x5 USB header

View and evidence limits

Per Table 3-1.

  • P345 USB 2.0 2x5 header — **Agree** on 1-8 and key 9; **pin 10 depends on implementation** — MSI manuals for different models agree on pin 10 NC; A's GIGABYTE and B's Intel Thin Mini-ITX agree. A's different Intel FPIO guide assigns over-current to 10. Preserve that explicit variant; do not replace it with a universal NC rule. No identical source document was used across passes here.
Internal USB 2.0 dual-port 2x5 header (pin 9 keyed) engineering referencePer Table 3-1.SCHEMATIC · physical positions unconfirmedNot to scale · check the named wiring and device manual1: VREG_FP_USBPWR0 (single_source)12: VREG_FP_USBPWR0 (single_source)23: USB_FP_P0- (single_source)34: USB_FP_P1- (single_source)45: USB_FP_P0+ (single_source)56: USB_FP_P1+ (single_source)67: Ground (single_source)78: Ground (single_source)89: Key (not_connected)910: USB_FP_OC0 (single_source)10powergrounddataConfigshieldNCUnknown
Schematic only · physical contact positions unconfirmed. Original drawing · not to scale. Scroll sideways if needed.
Intel Front Panel I/O Design Guide 2x5 USB header — source-scoped contact map
PinSignalWhat it doesStatus
1VREG_FP_USBPWR0Control, detection or configuration connection; check the source and device.Single source
Sources
2VREG_FP_USBPWR0Control, detection or configuration connection; check the source and device.Single source
Sources
3USB_FP_P0-Control, detection or configuration connection; check the source and device.Single source
Sources
4USB_FP_P1-Control, detection or configuration connection; check the source and device.Single source
Sources
5USB_FP_P0+Control, detection or configuration connection; check the source and device.Single source
Sources
6USB_FP_P1+Control, detection or configuration connection; check the source and device.Single source
Sources
7GroundGround reference and return.Single source
Sources
8GroundGround reference and return.Single source
Sources
9KeyNot connected or absent in this named wiring.Not connected
Sources
10USB_FP_OC0Control, detection or configuration connection; check the source and device.Single source
Sources
Sources (1)

MSI MAG B550 TOMAHAWK JUSB1~2

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

View and evidence limits

Per manual.

  • P345 USB 2.0 2x5 header — **Agree** on 1-8 and key 9; **pin 10 depends on implementation** — MSI manuals for different models agree on pin 10 NC; A's GIGABYTE and B's Intel Thin Mini-ITX agree. A's different Intel FPIO guide assigns over-current to 10. Preserve that explicit variant; do not replace it with a universal NC rule. No identical source document was used across passes here.
Internal USB 2.0 dual-port 2x5 header (pin 9 keyed) engineering referencePer manual.SCHEMATIC · physical positions unconfirmedNot to scale · check the named wiring and device manual1: VCC (device_specific)12: VCC (device_specific)23: USB0- (device_specific)34: USB1- (device_specific)45: USB0+ (device_specific)56: USB1+ (device_specific)67: Ground (device_specific)78: Ground (device_specific)89: No Pin (not_connected)910: NC (not_connected)10powergrounddataConfigshieldNCUnknown
Schematic only · physical contact positions unconfirmed. Original drawing · not to scale. Scroll sideways if needed.
MSI MAG B550 TOMAHAWK JUSB1~2 — source-scoped contact map
PinSignalWhat it doesStatus
1VCCPower connection (VCC). Check the specified supply.Device-specific
Sources
2VCCPower connection (VCC). Check the specified supply.Device-specific
Sources
3USB0-Control, detection or configuration connection; check the source and device.Device-specific
Sources
4USB1-Control, detection or configuration connection; check the source and device.Device-specific
Sources
5USB0+Control, detection or configuration connection; check the source and device.Device-specific
Sources
6USB1+Control, detection or configuration connection; check the source and device.Device-specific
Sources
7GroundGround reference and return.Device-specific
Sources
8GroundGround reference and return.Device-specific
Sources
9No PinNot connected or absent in this named wiring.Not connected
Sources
10NCNot connected or absent in this named wiring.Not connected
Sources
Sources (1)

GIGABYTE B550 AORUS ELITE (AX) F_USB1/F_USB2

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

View and evidence limits

Per manual.

  • P345 USB 2.0 2x5 header — **Agree** on 1-8 and key 9; **pin 10 depends on implementation** — MSI manuals for different models agree on pin 10 NC; A's GIGABYTE and B's Intel Thin Mini-ITX agree. A's different Intel FPIO guide assigns over-current to 10. Preserve that explicit variant; do not replace it with a universal NC rule. No identical source document was used across passes here.
Internal USB 2.0 dual-port 2x5 header (pin 9 keyed) engineering referencePer manual.SCHEMATIC · physical positions unconfirmedNot to scale · check the named wiring and device manual1: Power (5V) (device_specific)12: Power (5V) (device_specific)23: USB DX- (device_specific)34: USB DY- (device_specific)45: USB DX+ (device_specific)56: USB DY+ (device_specific)67: GND (device_specific)78: GND (device_specific)89: No Pin (not_connected)910: NC (not_connected)10powergrounddataConfigshieldNCUnknown
Schematic only · physical contact positions unconfirmed. Original drawing · not to scale. Scroll sideways if needed.
GIGABYTE B550 AORUS ELITE (AX) F_USB1/F_USB2 — source-scoped contact map
PinSignalWhat it doesStatus
1Power (5V)Power connection (Power (5V)). Check the specified supply.Device-specific
Sources
2Power (5V)Power connection (Power (5V)). Check the specified supply.Device-specific
Sources
3USB DX-Control, detection or configuration connection; check the source and device.Device-specific
Sources
4USB DY-Control, detection or configuration connection; check the source and device.Device-specific
Sources
5USB DX+Control, detection or configuration connection; check the source and device.Device-specific
Sources
6USB DY+Control, detection or configuration connection; check the source and device.Device-specific
Sources
7GNDGround reference and return.Device-specific
Sources
8GNDGround reference and return.Device-specific
Sources
9No PinNot connected or absent in this named wiring.Not connected
Sources
10NCNot connected or absent in this named wiring.Not connected
Sources
Sources (1)

Intel Thin Mini-ITX front-panel USB 2.0, pin-9 key

View and evidence limits

Figure 2-8 motherboard-header illustration: key lower right, No Connect directly above it, with two separately labeled USB-port rows. Table 2-9 supplies numbers; cable wire-side orientation is not labeled.

  • P345 USB 2.0 2x5 header — **Agree** on 1-8 and key 9; **pin 10 depends on implementation** — MSI manuals for different models agree on pin 10 NC; A's GIGABYTE and B's Intel Thin Mini-ITX agree. A's different Intel FPIO guide assigns over-current to 10. Preserve that explicit variant; do not replace it with a universal NC rule. No identical source document was used across passes here.
  • Nominal 2.54 mm pitch in this guide. The adjacent internal header keyed at both 9 and 10 (Table 2-10) is distinct and not merged here.
  • MSI table does not explicitly state VCC voltage. Other boards, proprietary headers and cable-rear orientation are unverified.
Internal USB 2.0 dual-port 2x5 header (pin 9 keyed) engineering referenceFigure 2-8 motherboard-header illustration: key lower right, No Connect directly above it, with two separately labeled USB-port rows. Table 2-9 supplies numbers; cable wire-side orientation is not labeled.SCHEMATIC · physical positions unconfirmedNot to scale · check the named wiring and device manual1: +5V DC (single_source)12: +5V DC (single_source)23: Data (negative) (single_source)34: Data (negative) (single_source)45: Data (positive) (single_source)56: Data (positive) (single_source)67: Ground (single_source)78: Ground (single_source)89: Key (no pin) (not_connected)910: No Connect (not_connected)10powergrounddataConfigshieldNCUnknown
Schematic only · physical contact positions unconfirmed. Original drawing · not to scale. Scroll sideways if needed.
Intel Thin Mini-ITX front-panel USB 2.0, pin-9 key — source-scoped contact map
PinSignalWhat it doesStatus
1+5V DCPower connection (+5V DC). Check the specified supply.Single source
Sources
2+5V DCPower connection (+5V DC). Check the specified supply.Single source
Sources
3Data (negative)Signal conductor. Pair, polarity and direction follow this named wiring.Single source
Sources
4Data (negative)Signal conductor. Pair, polarity and direction follow this named wiring.Single source
Sources
5Data (positive)Signal conductor. Pair, polarity and direction follow this named wiring.Single source
Sources
6Data (positive)Signal conductor. Pair, polarity and direction follow this named wiring.Single source
Sources
7GroundGround reference and return.Single source
Sources
8GroundGround reference and return.Single source
Sources
9Key (no pin)Not connected or absent in this named wiring.Not connected
Sources
10No ConnectNot connected or absent in this named wiring.Not connected
Sources
Sources (1)

MSI B550-A PRO JUSB1–2

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

View and evidence limits

MSI p.37 board drawing: 2 upper left, 10 upper right, 1 lower left, absent 9 lower right. Cable rear not established.

  • P345 USB 2.0 2x5 header — **Agree** on 1-8 and key 9; **pin 10 depends on implementation** — MSI manuals for different models agree on pin 10 NC; A's GIGABYTE and B's Intel Thin Mini-ITX agree. A's different Intel FPIO guide assigns over-current to 10. Preserve that explicit variant; do not replace it with a universal NC rule. No identical source document was used across passes here.
  • MSI table does not explicitly state VCC voltage. Other boards, proprietary headers and cable-rear orientation are unverified.
Internal USB 2.0 dual-port 2x5 header (pin 9 keyed) engineering referenceMSI p.37 board drawing: 2 upper left, 10 upper right, 1 lower left, absent 9 lower right. Cable rear not established.SCHEMATIC · physical positions unconfirmedNot to scale · check the named wiring and device manual1: VCC (device_specific)12: VCC (device_specific)23: USB0- (device_specific)34: USB1- (device_specific)45: USB0+ (device_specific)56: USB1+ (device_specific)67: Ground (device_specific)78: Ground (device_specific)89: No Pin (not_connected)910: NC (not_connected)10powergrounddataConfigshieldNCUnknown
Schematic only · physical contact positions unconfirmed. Original drawing · not to scale. Scroll sideways if needed.
MSI B550-A PRO JUSB1–2 — source-scoped contact map
PinSignalWhat it doesStatus
1VCCPower connection (VCC). Check the specified supply.Device-specific
Sources
2VCCPower connection (VCC). Check the specified supply.Device-specific
Sources
3USB0-Control, detection or configuration connection; check the source and device.Device-specific
Sources
4USB1-Control, detection or configuration connection; check the source and device.Device-specific
Sources
5USB0+Control, detection or configuration connection; check the source and device.Device-specific
Sources
6USB1+Control, detection or configuration connection; check the source and device.Device-specific
Sources
7GroundGround reference and return.Device-specific
Sources
8GroundGround reference and return.Device-specific
Sources
9No PinNot connected or absent in this named wiring.Not connected
Sources
10NCNot connected or absent in this named wiring.Not connected
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 JUSB1–2. Two rows with the absent position at a row end in this source view. A front-panel USB header, not the audio header. Read the board label and exact header diagram before selecting a front-panel cable. Still unresolved: Unidentified board variant, cable orientation and any proprietary front-panel harness. See the internal-header field reference for source revision, observation limits and the comparison.

Your next step

Move from the form to the requirement.

Read the engineering reference Source-scoped details, orientation and explicit unknowns.Work through a connection Choose your task before deciding on a cable.Explore this evidence trail Inspect the claims and their dependencies. (private workspace)

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 ↑
C345ASource checked · pending review

Intel’s Thin Mini-ITX design guide specifies a front-panel dual USB 2.0 2×5 header at 2.54 mm pitch, keyed by absent pin 9.

Intel · Thin Mini-ITX Based PC System Design Guide, Revision 1.2 ↗

Locator: PDF page 21, §2.3.1 Fig 2-5 HD Audio 2x5 key at pin 8; page 24, §2.5.1 Fig 2-8 dual USB 2x5 key at pin 9; p25 alternate double-key variant
Access: public pdf text. Original paraphrase of figures inspected visually. No Intel diagrams, pinout tables or copyrighted screenshots redistributed.

S456: 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 ↑
C345BSource checked · pending review

The same guide separately documents a dual internal USB 2.0 variant keyed at both positions 9 and 10; the keying must be identified explicitly.

Intel · Thin Mini-ITX Based PC System Design Guide, Revision 1.2 ↗

Locator: PDF page 21, §2.3.1 Fig 2-5 HD Audio 2x5 key at pin 8; page 24, §2.5.1 Fig 2-8 dual USB 2x5 key at pin 9; p25 alternate double-key variant
Access: public pdf text. Original paraphrase of figures inspected visually. No Intel diagrams, pinout tables or copyrighted screenshots redistributed.

S456: 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 ↑
C345CSource checked · pending review

B550-A PRO assigns JUSB1–2 to front-panel USB 2.0 ports, separately from JUSB3 and JUSB4.

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 ↑
C345DSource checked · pending review

Its JUSB1–2 table distinguishes absent position 9 from present but unconnected position 10.

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 ↑
C345ESource checked · pending review

MSI warns that incorrect USB-header power/ground connections can damage equipment.

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.

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Put this field note to work.

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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

S456 · Thin Mini-ITX Based PC System Design Guide, Revision 1.2

Intel · Manufacturer / product-owner domain · inspected 2026-10-09 · due 2027-01-07

Within inspection window

Scoped support: Explicit Intel Thin Mini-ITX examples, both documented as nominal 2.54 mm headers; not universal to all motherboards.

Not established / limitations: Original paraphrase of figures inspected visually. No Intel diagrams, pinout tables or copyrighted screenshots redistributed.

Locator: PDF page 21, §2.3.1 Fig 2-5 HD Audio 2x5 key at pin 8; page 24, §2.5.1 Fig 2-8 dual USB 2x5 key at pin 9; p25 alternate double-key variant

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

C345A · P345

Intel’s Thin Mini-ITX design guide specifies a front-panel dual USB 2.0 2×5 header at 2.54 mm pitch, keyed by absent pin 9.

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

Source links: S456 · Evidence trail → (private workspace)

C345B · P345

The same guide separately documents a dual internal USB 2.0 variant keyed at both positions 9 and 10; the keying must be identified explicitly.

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

Source links: S456 · Evidence trail → (private workspace)

C345C · P345

B550-A PRO assigns JUSB1–2 to front-panel USB 2.0 ports, separately from JUSB3 and JUSB4.

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)

C345D · P345

Its JUSB1–2 table distinguishes absent position 9 from present but unconnected position 10.

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)

C345E · P345

MSI warns that incorrect USB-header power/ground connections can damage equipment.

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.