Video & projection
AJA IO series (Thunderbolt I/O) troubleshooting
The AJA IO series (Thunderbolt I/O) problems live-event techs bring to Ask Roadie most (also called IO 4K, IO 4K Plus, IO X3). Pick your symptom, or describe your own in plain words, and get the likeliest fix first, with the manual page when there is one.
Common IO series (Thunderbolt I/O) errors & problems
What techs run into most, and what's usually behind it. The step-by-step fix for your exact unit is in Ask Roadie.
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Certain HDMI sources are not received / no HDMI input
Likely cause: v17 fixed the HDMI signal-reception defect; a marginal cable or unsupported format can otherwise present as no input.
- Step-by-step fixGet the fix →
Dropped frames during capture or extended playback
Likely cause: Dropped frames are almost always a storage-throughput or shared-Thunderbolt-bandwidth ceiling; System Test verifies the disk, and dedicating the bus removes contention.
- Step-by-step fixGet the fix →
Fans spin up but Io 4K Plus does not appear in AJA Control Panel / apps on a Mac
Likely cause: macOS blocks third-party drivers until the user explicitly allows them in Security settings; the extension load is what actually binds the Thunderbolt device to Control Panel.
- Step-by-step fixGet the fix →
How to update firmware on the Io 4K Plus
Likely cause: AJA ships a unified driver+firmware package; the on-device firmware only updates when Control Panel flashes it and the unit is power-cycled, so skipping the power-cycle leaves old firmware running.
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Intermittent connection or device drops when daisy-chained through a hub or display
Likely cause: Downstream position behind a display/dock can starve the Io of Thunderbolt bandwidth and cause dropouts; direct/first-in-chain placement with a full-spec cable guarantees the throughput 12G/4K needs.
- Step-by-step fixGet the fix →
Io 4K Plus is completely dead / no power
Likely cause: The Io 4K Plus requires external DC power through the 4-pin XLR; Thunderbolt carries data only for this unit, so a missing/failed adapter looks like a dead device.
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Io 4K Plus will not lock to a YUV 4:2:2 signal
Likely cause: v18 addressed a specific 4:2:2 lock defect on the Io 4K Plus; the fix is delivered as firmware inside the v18 package and takes effect after the device firmware is updated.
- Step-by-step fixGet the fix →
No analog audio, or analog audio breakout wired incorrectly
Likely cause: The Io 4K Plus multiplexes 8 balanced analog channels over one TASCAM-pinout DB-25; a non-TASCAM cable or wrong direction setting yields missing/incorrect channels.
- Step-by-step fixGet the fix →
Output flashing and AJA Control Panel shows "Unknown Format" when using a tri-level sync genlock reference in playback
Likely cause: v17 corrected a firmware/driver defect where tri-level sync in Playback Lock produced Unknown Format and flashing output; the reference format must match the video format to genlock cleanly.
Not on the list? Describe it your way, or paste the error code off the display. Ask Roadie works the problem with you until it's fixed or you have a clear next move.
How Ask Roadie helps with the IO series (Thunderbolt I/O)
- 1. Pick the AJA IO series (Thunderbolt I/O). It's already in the list.
- 2. Describe what you're seeing. In your own words, or the error code off the screen.
- 3. Get the likeliest fix first. Steps in order, the manual page when there is one, and a note when other techs have confirmed it.
- 4. Still broken? Tap 👎 and it keeps going from where you left off.
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