P085 / Thunderbolt / Guide
Choose the host port on a dock
Name the upstream host link before counting the other sockets.
Guide library
Make the next connection clearer.
Browse the source-linked collection. Every record separates documented facts from the things a shape or label cannot tell you.
90 field notes
Source checked · independent review pendingUSB, Thunderbolt & mobile
USB plugs and ports, Thunderbolt and Lightning.
6 records
P082 / USB / Guide
Front and rear USB-C ports can have different roles
Match the documented port location before transferring a capability.
P088 / USB / Guide
Record a USB transfer requirement precisely
A complete USB task names a mode, device role and workload.
P083 / USB / Guide
USB monitor upstream and downstream ports
The right shape in the wrong role is still the wrong evidence.
P052 / USB / Guide
USB-C and Thunderbolt 5: connector versus technology
This comparison is between different layers, not two competing plug shapes.
P054 / USB / Guide
Why a USB-C port may not provide video
A working charge or data connection is not a video test.
Display & video
HDMI, DisplayPort, DVI, VGA, analog video and docks.
16 records
P086 / Video / Guide
A dock port count is not a simultaneous display claim
Count requirements and shared resources, not just connectors.
P160 / Dock and display connections / Guide
A reviewable multi-display checklist
Physical outputs, rendering engines, exact models and observed requirements are separate evidence.
P053 / Video / Guide
DisplayPort and HDMI: how to choose a connection
Choose the documented path for your task, not a universal winner.
P084 / Video / Guide
DisplayPort input and output are separate roles
Read the input/output label before treating sockets as interchangeable.
P087 / Video / Guide
Find the Raspberry Pi display connector by model
Use the model-specific port map rather than guessing from board size.
P155 / Dock and display connections / Guide
MacBook display limits: count the chip, not the sockets
Physical outputs, rendering engines, exact models and observed requirements are separate evidence.
P051 / Video / Guide
Mini HDMI versus Micro HDMI
Start with the full connector name, not the word “small”.
P158 / Dock and display connections / Guide
Monitor inputs, physical units and reference modes
Physical outputs, rendering engines, exact models and observed requirements are separate evidence.
P156 / Dock and display connections / Guide
More sockets do not mean more independent displays
Physical outputs, rendering engines, exact models and observed requirements are separate evidence.
P157 / Dock and display connections / Guide
Native, DisplayLink and hybrid dock outputs
Physical outputs, rendering engines, exact models and observed requirements are separate evidence.
P159 / Dock and display connections / Guide
Read a dock resolution table without guessing
Physical outputs, rendering engines, exact models and observed requirements are separate evidence.
P079 / Video / Guide
Video bandwidth: active picture versus the link
Active-picture arithmetic is useful, but it is not a cable verdict.
P056 / Video / Guide
What to check for USB-C 4K 144 Hz
“4K 144 Hz” is the start of a requirements list.
P078 / Video / Guide
Why dock ports do not guarantee extra displays
Count supported display paths, not only visible sockets.
Audio
Jacks, XLR, RCA, optical audio and interface wiring.
8 records
P149 / Audio connections / Guide
Audio connections: identify the signal before the plug
Document signal role, channel layout and power separately from connector shape.
P153 / Audio connections / Guide
Audio interfaces: shared inputs are not extra channels
Document signal role, channel layout and power separately from connector shape.
P151 / Audio connections / Guide
Balanced mono is not stereo headphones
Document signal role, channel layout and power separately from connector shape.
P154 / Audio connections / Guide
Direct boxes, source conflicts and audio patch reports
Document signal role, channel layout and power separately from connector shape.
P152 / Audio connections / Guide
Interface to active monitors: one channel per speaker
Document signal role, channel layout and power separately from connector shape.
P135 / Audio / Guide
Loudspeaker connectors are not general power connectors
Do not turn a familiar connector into a power substitute.
P130 / Audio / Guide
MIDI DIN and audio plugs: separate shape from transport
Name the signal before the plug.
P150 / Audio connections / Guide
Phantom power: requirement, supply and switch state
Document signal role, channel layout and power separately from connector shape.
Power & charging
Mains, DC barrel, appliance couplers and charging.
20 records
P163 / Charging and power / Guide
A charging cable’s wattage is not its data speed
Source output, occupied ports, requested power and cable evidence are separate.
P168 / Charging and power / Guide
A fast-charge setup is not a universal minimum
A named adapter-and-cable setup does not justify a generic minimum for every charger.
P176 / Charging and power / Guide
An upper voltage is not a complete PPS range
Keep exact source scope, profile alternatives, numerical bounds and physical observations separate.
P172 / Charging and power / Guide
Build a reviewable device-power worksheet
Start with the exact device, identify the goal, then compare source and cable evidence.
P060 / Power / Guide
Charging watts versus data speed: independent requirements
Watts and Gbit/s answer different questions.
P170 / Charging and power / Guide
Check cable current, not just cable watts
Use explicit voltage and current evidence rather than deriving either from wattage alone.
P175 / Charging and power / Guide
Check voltage, current and power as separate ceilings
Keep exact source scope, profile alternatives, numerical bounds and physical observations separate.
P164 / Charging and power / Guide
Fast charging needs the exact model and cable path
Source output, occupied ports, requested power and cable evidence are separate.
P173 / Charging and power / Guide
Fixed output or PPS: read the documented option
Keep exact source scope, profile alternatives, numerical bounds and physical observations separate.
P166 / Charging and power / Guide
Make a reviewable charging checklist
Source output, occupied ports, requested power and cable evidence are separate.
P178 / Charging and power / Guide
Prepare a reviewable output-profile report
Keep exact source scope, profile alternatives, numerical bounds and physical observations separate.
P161 / Charging and power / Guide
Read a charger’s port-sharing table
Source output, occupied ports, requested power and cable evidence are separate.
P167 / Charging and power / Guide
Recommended supply is not measured demand
Pi supply recommendations and peripheral allowances show why a single wattage is not the whole question.
P177 / Charging and power / Guide
The cable has its own current and voltage limits
Keep exact source scope, profile alternatives, numerical bounds and physical observations separate.
P174 / Charging and power / Guide
The same charger family can have different published ranges
Keep exact source scope, profile alternatives, numerical bounds and physical observations separate.
P162 / Charging and power / Guide
Watts, volts and amps answer different questions
Source output, occupied ports, requested power and cable evidence are separate.
P169 / Charging and power / Guide
What an included adapter tells you
Keep a bundled supply rating out of demand arithmetic unless the source separately defines a requirement.
P171 / Charging and power / Guide
When two charging sources describe different goals
Keep the exact goal and its source visible instead of silently choosing one number.
P059 / Power / Guide
Why a barrel plug that fits may be incompatible
Stop at identifying the connector. Do not try an unknown supply.
P165 / Charging and power / Guide
Why another device can change charger output
Source output, occupied ports, requested power and cable evidence are separate.
Network, fiber & telephone
Ethernet, PoE, fiber, modular phone and pluggable optics.
8 records
P146 / Ethernet and PoE / Guide
An injector has two different sides
A documented model, port role, rate or budget is not a verified physical connection.
P143 / Ethernet and PoE / Guide
Ethernet rates: the plug is only the beginning
A documented model, port role, rate or budget is not a verified physical connection.
P147 / Ethernet and PoE / Guide
Extend mode and hardware revisions change the question
A documented model, port role, rate or budget is not a verified physical connection.
P136 / Fiber / Guide
Fiber identification without unsafe end-face inspection
Never look into an unknown fiber.
P148 / Ethernet and PoE / Guide
Network evidence: unknowns, conflicts and reference reports
A documented model, port role, rate or budget is not a verified physical connection.
P145 / Ethernet and PoE / Guide
PoE budget: reserved output is not device draw
A documented model, port role, rate or budget is not a verified physical connection.
P144 / Ethernet and PoE / Guide
PoE: distinguish the source from the powered device
A documented model, port role, rate or budget is not a verified physical connection.
P131 / Telephone / Guide
Telephone plugs: positions, contacts and port roles
A trade name is not a wiring specification.
Storage & memory
SATA, SAS, M.2, U.2 and memory cards.
11 records
P142 / Memory cards / Guide
A non-destructive card-offload planning checklist
Keep the original media until your own backup verification is complete.
P137 / Memory cards / Guide
Choose a card reader without guessing from its shape
A reader with the same exterior connector can support a different set of media.
P133 / Storage / Guide
CompactFlash, CFast and CFexpress: choose the card family first
Similar names do not make interchangeable cards.
P057 / Storage / Guide
M.2 versus NVMe: different categories
Check the slot specification, not just the notch.
P139 / Memory cards / Guide
Read a camera card-slot map correctly
Alternative families in one slot do not create extra slots.
P141 / Memory cards / Guide
Recording support is not the same as offload support
Family support does not establish a recording mode or sustained throughput.
P076 / Storage / Guide
SD capacity, bus speed and speed class
Three different labels answer three different questions.
P075 / Storage / Guide
SD versus microSD: start with the form factor
Compare physical form first; keep the remaining requirements separate.
P140 / Memory cards / Guide
The reader-to-computer USB checklist
A documented USB-C port is not a verified cable, driver or transfer rate.
P138 / Memory cards / Guide
XQD and CFexpress: check the reader, not just the outline
An explicit support statement is more useful than a successful-looking fit.
P134 / Storage / Guide
XQD versus CFexpress Type B: check support, not just fit
Same form factor, separate support decisions.
Coax, RF & legacy
BNC, F-type, SMA and micro RF, FireWire and legacy computer ports.
3 records
P132 / Legacy computer / Guide
D-sub identification does not determine the port function
Find the interface name in the manual.
P129 / FireWire / Guide
Identify a FireWire cable before planning a transfer
Start at both ends, not at an adapter listing.
P077 / Coax / Guide
SMA versus RP-SMA: inspect the center contact
Look at both the shell and the contact before naming the interface.
Working methods
How to read labels, models, sources and failure reports.
18 records
P101 / General / Guide
A Focusrite USB interface is not detected
Observe one change at a time. Keep the scope and stop conditions visible.
P098 / General / Guide
A Mac display offers the wrong mode
Observe one change at a time. Keep the scope and stop conditions visible.
P097 / General / Guide
A Mac display stays dark
Observe one change at a time. Keep the scope and stop conditions visible.
P103 / General / Guide
A Mac reports USB devices disabled
Observe one change at a time. Keep the scope and stop conditions visible.
P102 / General / Guide
A storage device is missing on a Mac
Observe one change at a time. Keep the scope and stop conditions visible.
P100 / General / Guide
A webcam is unavailable in Windows
Observe one change at a time. Keep the scope and stop conditions visible.
P094 / General / Guide
A webcam mode needs more than a USB-C plug
Write down the video format, not only the connector.
P104 / General / Guide
An original Facecam reports a USB requirement
Observe one change at a time. Keep the scope and stop conditions visible.
P090 / General / Guide
Capture cable identity, length and direction
Write down the exact product before reasoning about its class.
P080 / General / Guide
Gigabits, gigabytes and transfer-time estimates
Keep the units exact and the throughput assumption visible.
P058 / General / Guide
How to identify a cable without relying on color
Use shape to narrow the candidates, then use documentation to establish function.
P095 / General / Guide
Read an external SSD interface without promising file speed
An interface label is not a measured file copy.
P081 / General / Guide
Read the exact model, not just the product family
A model name is the beginning of the evidence, not the end.
P096 / General / Guide
USB-C can carry a USB 2.0 audio connection
Shape and data generation are separate facts.
P093 / General / Guide
USB-C power input or data port? Read the device label
Same connector shape. Different job.
P092 / General / Guide
Use a source page without inheriting every claim
A citation supports a scoped statement, not every possible inference.
P099 / General / Guide
Windows does not show the external display
Observe one change at a time. Keep the scope and stop conditions visible.
P091 / General / Guide
Write a useful connection failure report
A reproducible report is more useful than a guessed diagnosis.