Causes
- The adapter is passive — video has to come from the laptop's port — the PowerExpand is a straight-through cable, not a video converter. If the USB-C port you plugged it into doesn't output DisplayPort Alt Mode (many laptops reserve video out for only one of their USB-C ports, and phones/tablets often don't output video at all), no adapter in the world will produce a picture. The port has to be DP Alt Mode-capable on the source side.
- A USB 2.0 or charge-only cable plugged into the adapter's female end — the extension's female socket accepts any USB-C cable, but the cable you insert decides whether video passes. A charge-only or USB 2.0 cable carries just the power pins and the low-speed data pair — no SuperSpeed lanes, no SBU pins — so the monitor gets nothing even though charging works perfectly.
- The high-speed pairs inside the 10cm extension broke — the four SuperSpeed TX/RX pairs and the two SBU pins (which DisplayPort Alt Mode uses for lane configuration) run through the 90° joint. Repeated bending, a hard yank, or a drop can snap those thin wires while the beefier power wires survive. The result: charging and USB data at low speed still work, but DP Alt Mode never negotiates — no picture, or a picture that only appears when the extension is held at exactly the right angle.
- DP Alt Mode needs all four lanes plus SBU end-to-end — for 4K@60Hz and above, the whole chain — laptop port, adapter extension, inserted cable, and monitor input — must carry four SuperSpeed lanes plus SBU1/SBU2. Any link in that chain rated below full USB 3.2 Gen 2 (10 Gbps) caps the video bandwidth, which shows up as no signal, flickering, or the monitor dropping to a lower resolution than expected.
- A partially seated head or dirty pins — the 90° head that doesn't click fully into the laptop port can make contact on the outer power pins while the inner SuperSpeed/SBU pins sit short — charging works, video doesn't. Pocket lint and oxidation on the small inner pins cause the same selective failure.
- Wrong input selected on the monitor, or a monitor that only takes video on one of its ports — a monitor with multiple USB-C/HDMI inputs may sit on the wrong input, or its USB-C port may be data-only with video only on HDMI/DP. The adapter can be perfectly healthy while the display simply isn't listening on that input.
How to Fix
- Confirm the source port outputs video — plug a USB-C to HDMI/DisplayPort cable directly into the laptop's USB-C port (no adapter) and see if the monitor wakes up. If it doesn't, the port doesn't output DP Alt Mode — try the laptop's other USB-C port (often only one is video-capable) or use a different port entirely. This is the first thing to verify, because no adapter fix will help if the source has no video signal.
- Swap the cable in the adapter's female end for a known-good video cable — use the USB-C cable that came with your monitor, or any cable you know carries video to a monitor directly. Charge-only and USB 2.0 cables are the most common reason "the adapter doesn't do video."
- Fully reseat both ends — unplug everything, push the 90° head into the laptop until you feel the retention click, and push the video cable fully into the adapter's female socket. A partial seat on the inner pins is the number one mechanical cause of no video through an angle adapter.
- Clean the contacts — blow lint out of the laptop port with compressed air, and wipe the adapter's male pins and female socket with isopropyl alcohol on a cotton swab. The tiny SuperSpeed/SBU pins are the first to lose contact when dirty.
- Check the monitor's input — switch the monitor to the correct input (USB-C, HDMI, or DP depending on what's connected), and confirm the monitor's USB-C port actually accepts video — some only charge or pass data. If the monitor has multiple USB-C ports, try the one labeled for video/DP.
- Do the flex test — with everything connected and the monitor on, gently flex the braided extension near the 90° joint. If the picture drops, flickers, or only appears at one angle, the SuperSpeed pairs are broken inside the extension — a physical failure no driver or cleaning will fix.
- Lower the resolution as a diagnostic — try 1080p instead of 4K. If 1080p works but 4K doesn't, the chain is losing lane bandwidth somewhere (usually a USB 2.0 cable or a damaged lane in the extension) — swap cables, then suspect the adapter itself.
- Replace it under warranty — if the flex test or lane-bandwidth test points at the adapter, Anker's 18-month warranty covers the PowerExpand line. Contact support.anker.com with your order number and describe the angle-dependent behavior; they'll ship a replacement.