E339 · Source-scoped pinout variants

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

Named wiring from the pinout research; connector shape alone does not establish capabilities.

Open field note Source trail

Source checked · no independent review claimed · Fabrication approved: no

Internal USB 2.0 dual-port 2x5 header (pin 9 keyed) engineering reference original orientation schematic — Original pinout diagram; read the exact variant and view below. Not to scale.

Contact count

Not asserted

Source-scoped connector interface

Mating boundary

Shape is not the verdict.

Check the exact device and mating connector.

Orientation

How to read this profile

Read the exact variant view convention. Schematic layouts do not establish physical positions.

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 rows	2 (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 pitch	2.54 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 role	PCB 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 / polarization	10positionoutlinewithpin9absent;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.
Manufacturer	MSI (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.
Series	B550-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 / implementation	B550-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 convention	Published 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 →

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.

Dark pinout view

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

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.

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
Pin	Signal	What it does	Status
1	VREG_FP_USBPWR0	Control, detection or configuration connection; check the source and device.	Single source Sources
2	VREG_FP_USBPWR0	Control, detection or configuration connection; check the source and device.	Single source Sources
3	USB_FP_P0-	Control, detection or configuration connection; check the source and device.	Single source Sources
4	USB_FP_P1-	Control, detection or configuration connection; check the source and device.	Single source Sources
5	USB_FP_P0+	Control, detection or configuration connection; check the source and device.	Single source Sources
6	USB_FP_P1+	Control, detection or configuration connection; check the source and device.	Single source Sources
7	Ground	Ground reference and return.	Single source Sources
8	Ground	Ground reference and return.	Single source Sources
9	Key	Not connected or absent in this named wiring.	Not connected Sources
10	USB_FP_OC0	Control, detection or configuration connection; check the source and device.	Single source Sources

Sources (1)

S839 · Intel Corporation · Front Panel I/O Connectivity Design Guide
Document 600569, Revision 1.1, July 2018 · Section 3.2.4, Table 3-1 Front Panel USB Connector, printed p. 20 (Figure 3-1 header design)

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.

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
Pin	Signal	What it does	Status
1	VCC	Power connection (VCC). Check the specified supply.	Device-specific Sources
2	VCC	Power connection (VCC). Check the specified supply.	Device-specific Sources
3	USB0-	Control, detection or configuration connection; check the source and device.	Device-specific Sources
4	USB1-	Control, detection or configuration connection; check the source and device.	Device-specific Sources
5	USB0+	Control, detection or configuration connection; check the source and device.	Device-specific Sources
6	USB1+	Control, detection or configuration connection; check the source and device.	Device-specific Sources
7	Ground	Ground reference and return.	Device-specific Sources
8	Ground	Ground reference and return.	Device-specific Sources
9	No Pin	Not connected or absent in this named wiring.	Not connected Sources
10	NC	Not connected or absent in this named wiring.	Not connected Sources

Sources (1)

S761 · Micro-Star International (MSI) · MAG B550 TOMAHAWK Motherboard User Guide (multilingual)
No revision printed; PDF creation date 2023-12-26 (file MAGB550TOMAHAWK.pdf) · English section, 'JUSB1~2: USB 2.0 Connectors' table, printed p. 22

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.

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
Pin	Signal	What it does	Status
1	Power (5V)	Power connection (Power (5V)). Check the specified supply.	Device-specific Sources
2	Power (5V)	Power connection (Power (5V)). Check the specified supply.	Device-specific Sources
3	USB DX-	Control, detection or configuration connection; check the source and device.	Device-specific Sources
4	USB DY-	Control, detection or configuration connection; check the source and device.	Device-specific Sources
5	USB DX+	Control, detection or configuration connection; check the source and device.	Device-specific Sources
6	USB DY+	Control, detection or configuration connection; check the source and device.	Device-specific Sources
7	GND	Ground reference and return.	Device-specific Sources
8	GND	Ground reference and return.	Device-specific Sources
9	No Pin	Not connected or absent in this named wiring.	Not connected Sources
10	NC	Not connected or absent in this named wiring.	Not connected Sources

Sources (1)

S762 · GIGA-BYTE Technology · B550 AORUS ELITE / B550 AORUS ELITE AX User's Manual
Rev. 1002, 12ME-B55AELT-1002R (copyright 2020) · Chapter 1, item 14) F_USB1/F_USB2 (USB 2.0/1.1 Headers) table, printed p. 20

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.

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
Pin	Signal	What it does	Status
1	+5V DC	Power connection (+5V DC). Check the specified supply.	Single source Sources
2	+5V DC	Power connection (+5V DC). Check the specified supply.	Single source Sources
3	Data (negative)	Signal conductor. Pair, polarity and direction follow this named wiring.	Single source Sources
4	Data (negative)	Signal conductor. Pair, polarity and direction follow this named wiring.	Single source Sources
5	Data (positive)	Signal conductor. Pair, polarity and direction follow this named wiring.	Single source Sources
6	Data (positive)	Signal conductor. Pair, polarity and direction follow this named wiring.	Single source Sources
7	Ground	Ground reference and return.	Single source Sources
8	Ground	Ground reference and return.	Single source Sources
9	Key (no pin)	Not connected or absent in this named wiring.	Not connected Sources
10	No Connect	Not connected or absent in this named wiring.	Not connected Sources

Sources (1)

S840 · Intel Corporation · Thin Mini-ITX Based PC System Design Guide
Revision 1.2, December 2012 · printed/PDF pp.24–25, section 2.5.1 Front Panel Dual USB 2.0 Header, Figure 2-8 and Table 2-9

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.

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
Pin	Signal	What it does	Status
1	VCC	Power connection (VCC). Check the specified supply.	Device-specific Sources
2	VCC	Power connection (VCC). Check the specified supply.	Device-specific Sources
3	USB0-	Control, detection or configuration connection; check the source and device.	Device-specific Sources
4	USB1-	Control, detection or configuration connection; check the source and device.	Device-specific Sources
5	USB0+	Control, detection or configuration connection; check the source and device.	Device-specific Sources
6	USB1+	Control, detection or configuration connection; check the source and device.	Device-specific Sources
7	Ground	Ground reference and return.	Device-specific Sources
8	Ground	Ground reference and return.	Device-specific Sources
9	No Pin	Not connected or absent in this named wiring.	Not connected Sources
10	NC	Not connected or absent in this named wiring.	Not connected Sources

Sources (1)

S757 · Micro-Star International (MSI) · B550-A PRO User Guide
Version 6.0, 2024/02, First release (Revision History, PDF p.59) · printed/PDF p.37, JUSB1~2: USB 2.0 Connectors, numbered drawing and Pin/Signal Name table

Unknowns stay unknown.

Check the exact device manual before wiring or applying power.

Your next step

Use the detail without guessing past its limits.

Read the connector field note Recognition clues and practical checks.Work through a connection Keep exact equipment and cable requirements separate.

Source trail

Claims and sources

C810Msource checked

Intel Front Panel I/O Design Guide 2x5 USB header: original contact normalization. Statuses distinguish comparison agreement, source limits and named-device wiring.

Intel Corporation · Front Panel I/O Connectivity Design Guide ↗
Section 2.3.5, Table 2-5 Front Panel Audio Header Signal Names, printed p. 18; compare Table 4-1 Audio Cable and Connector Pin Assignments, printed p. 26; Section 3.2.4, Table 3-1 Front Panel USB Connector, printed p. 20 (Figure 3-1 header design) · Source scope and unresolved evidence are preserved in the engineering variant.

C810Nsource checked

MSI MAG B550 TOMAHAWK JUSB1~2: original contact normalization. Statuses distinguish comparison agreement, source limits and named-device wiring.

Micro-Star International (MSI) · MAG B550 TOMAHAWK Motherboard User Guide (multilingual) ↗
English section, 'CPU_FAN1, PUMP_FAN1, SYS_FAN1~6: Fan Connectors', PWM Mode and DC Mode pin definition tables, printed p. 23; English section, 'CPU_PWR1, ATX_PWR1: Power Connectors', CPU_PWR1 table, printed p. 20; English section, 'JAUD1: Front Audio Connector' table, printed p. 19; English section, 'JRAINBOW1~2: Addressable RGB LED connectors' table, printed p. 27; English section, 'JRGB1~2: RGB LED connectors' table, printed p. 26; English section, 'JUSB1~2: USB 2.0 Connectors' table, printed p. 22; English section, Overview of Components, 'CPU_PWR1, ATX_PWR1: Power Connectors', ATX_PWR1 table, printed p. 20 · Source scope and unresolved evidence are preserved in the engineering variant.

C810Osource checked

GIGABYTE B550 AORUS ELITE (AX) F_USB1/F_USB2: original contact normalization. Statuses distinguish comparison agreement, source limits and named-device wiring.

GIGA-BYTE Technology · B550 AORUS ELITE / B550 AORUS ELITE AX User's Manual ↗
Chapter 1, item 1/2) ATX_12V/ATX, 'ATX:' pin table, printed p. 15; Chapter 1, item 1/2) ATX_12V/ATX, 'ATX_12V:' pin table, printed p. 15; Chapter 1, item 12) F_AUDIO (Front Panel Audio Header), High Definition audio table, printed p. 19; Chapter 1, item 14) F_USB1/F_USB2 (USB 2.0/1.1 Headers) table, printed p. 20; Chapter 1, item 3/4) CPU_FAN/SYS_FAN1/2/3 (Fan Headers) pin table, printed p. 15; item 5) CPU_OPT, printed p. 16; Chapter 1, item 7) D_LED1/D_LED2 (Addressable LED Strip Headers), printed p. 16; Chapter 1, item 8) LED_C1/LED_C2 (RGB LED Strip Headers), printed p. 17; item 6) LED_CPU, printed p. 16 · Source scope and unresolved evidence are preserved in the engineering variant.

C810Psource checked

Intel Thin Mini-ITX front-panel USB 2.0, pin-9 key: original contact normalization. Statuses distinguish comparison agreement, source limits and named-device wiring.

Intel Corporation · Thin Mini-ITX Based PC System Design Guide ↗
printed/PDF p.21, section 2.3.1 Front Panel Audio, Figure 2-5 and Table 2-5: Passive AC’97 Front Panel Audio Header Pin-Out; printed/PDF pp.21–22, section 2.3.1 Front Panel Audio, Figure 2-5 and Table 2-6: HD Audio Front Panel Audio Header Pin-Out; printed/PDF pp.24–25, section 2.5.1 Front Panel Dual USB 2.0 Header, Figure 2-8 and Table 2-9 · Source scope and unresolved evidence are preserved in the engineering variant.

C810Qsource checked

MSI B550-A PRO JUSB1–2: original contact normalization. Statuses distinguish comparison agreement, source limits and named-device wiring.

Micro-Star International (MSI) · B550-A PRO User Guide ↗
printed/PDF p.33, JAUD1: Front Audio Connector, numbered drawing and Pin/Signal Name table; printed/PDF p.34, CPU_PWR1, ATX_PWR1: Power Connectors, ATX_PWR1, numbered drawing and Pin/Signal Name table; printed/PDF p.34, CPU_PWR1, ATX_PWR1: Power Connectors, CPU_PWR1, numbered drawing and Pin/Signal Name table; printed/PDF p.37, JUSB1~2: USB 2.0 Connectors, numbered drawing and Pin/Signal Name table; printed/PDF p.38, CPU_FAN1, PUMP_FAN1, SYS_FAN1~6: Fan Connectors, PWM Mode and DC Mode pin definition tables and mode explanation, numbered drawing and Pin/Signal Name table; printed/PDF p.40, JRGB1: RGB LED connector, numbered drawing and Pin/Signal Name table; printed/PDF p.41, JRAINBOW1~2: Addressable RGB LED connectors, numbered drawing and Pin/Signal Name table · Source scope and unresolved evidence are preserved in the engineering variant.

5 source records support this profile. No independent engineering review or hardware validation is claimed.

Evidence behind this page

Scope first. Source second. Approval separate.

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

Page scope: Original schematic; not to scale and not fabrication approval.

Assessment 2026-10-22 · earliest scheduled source review 2027-01-18. This is a recorded-date assessment, not a live source check. Page-level independent review is not established by this panel.

Inspect 5 source scopes, access limits and dates

S757 · B550-A PRO User Guide

Micro-Star International (MSI) · Unclassified publisher domain · inspected 2026-10-21 · due 2027-01-19

Within inspection window

Scoped support: Exact named pinout variant only; not capability or compatibility approval.