Why Your USB-C Cable Won't Charge or Carry Video

USB-C's greatest feature is also its trap: every cable has the identical plug, and almost nothing else in common. The cable that charges your phone may not move data faster than a 2005 thumb drive, and the one that moves data fast may not drive your monitor. None of this is visible from the outside.

Three separate capabilities, one connector

• Data: a USB-C cable can be wired for USB 2.0 (480Mbps — very common in charge cables), 5Gbps, 10Gbps, or 20Gbps. If your external SSD is crawling, the cable is suspect number one.
• Power: standard cables handle 3A (60W). Charging above that — 100W-class laptops — requires a 5A cable with an e-marker chip. A 3A cable on a big laptop doesn't fail; it just charges slowly.
• Video: driving a monitor over USB-C uses DisplayPort Alt Mode, which needs a full-featured cable wired with the high-speed lanes. Charge-only cables physically lack those wires — no setting can fix that.

How to buy (and troubleshoot) correctly

Ignore the plug; read the spec. Every USB cable we list states its generation, speed and amperage outright — like our 10Gbps USB 3.2 Gen 2 C-to-C and C-to-A cables with 3A charging, and full-function extension cables that carry 4K@60Hz video alongside data and power. For older peripherals, honest USB 2.0 and 3.0 cables cost less and do that job perfectly.

The 60-second diagnosis

Monitor won't light up over USB-C? First confirm your laptop's port supports DP Alt Mode (many budget laptops' ports are charge/data only), then swap in a known full-featured cable. Slow file transfers? Check the cable's rated speed before blaming the drive. Slow charging? You may be on a 480Mbps/3A phone cable — fine for overnight, wrong for a workstation.

Adapters and converters have the same hidden-spec problem — our USB-C adapter collection states exactly what each one converts. Stuck on a specific device pairing? Ask us — include both device models and we'll match the cable.