OREI UHD-EXB400R-K 4K HDBaseT HDMI Extender Troubleshooting Guide – OREI

Introduction

This troubleshooting guide helps you diagnose and resolve common issues with the OREI UHD-EXB400R-K 4K HDBaseT HDMI Extender over Cat 5e/6/7. The UHD-EXB400R-K is a 1-to-1 HDBaseT extender kit that supports 4K at 60 Hz 4:4:4 up to 400 ft over Cat 6 or Cat 7, with Power over Cable, bi-directional IR, CEC, RS-232, HDMI loop out on the transmitter, and audio out on the receiver. It also supports HDR and HDCP 2.2.

Issue description

Use this guide when the extender is not linking, not passing video, not supporting the expected resolution, or when control features such as IR, CEC, or RS-232 are not working as expected. Because the transmitter and receiver are sold as a matched kit, troubleshooting should always be performed on the complete set.

Signs

No link light on the transmitter or receiver
No video on the display
4K resolution is not passing or is limited to a lower resolution
HDR10+ is not passing through as expected
The unit worked for a period of time and then stopped
Audio is missing or intermittent
IR remote control is not working reliably
CEC is not working
RS-232 control is not working
The extender is not working at all

Basic troubleshooting steps

Confirm the source device is powered on and outputting a signal.
Try changing the HDMI cables.
Power cycle the transmitter, receiver, source, and display.
Test the source directly to the display to confirm the source and HDMI cables are working.
Use Cat 6 or Cat 7 cable for best performance, especially for 4K at 60 Hz.
Confirm the Cat cable terminations are wired to T568B on both ends.
Check for adequate ventilation and remove any heat buildup around the units.
Try a different media source.

Advanced troubleshooting steps

1. No link light on the transmitter or receiver

There are two LEDs on the CAT ports on the Transmitter and Receiver, Green and Yellow. The Green LED represents power and Yellow represents the signal. If the Yellow LED does not come up but the green one does, it could mean no media source is connected or the media source is not outputting a signal. So, check the media source first. If media source is confirmed to be active;

Verify T568B wiring on both ends of the Cat cable.
Try changing the CAT cable.
Use Cat 6 if available; Cat 5e is supported, but Cat 6 is recommended for better reliability.
Try a different media source if possible.
If neither unit shows a link light after trying multiple cables, the unit may be defective.

2. No video on the display

If the link light is present but there is no image on the display, the issue is often related to the source signal, HDMI cabling, or display input selection.

Try changing the HDMI cable.
Use a different media source, if possible.
Power cycle the transmitter and receiver.
Connect a display to the HDMI Output on the Transmitter and check if it works.
Try changing the CAT cable.
Try a lower resolution from the media source.
Check if the media source works when connected directly to the display.

3. 4K resolution not passing or limited to 1080p

The UHD-EXB400R-K supports 4K at 60 Hz 4:4:4 up to 400 ft over Cat 6 or Cat 7. Beyond 400 ft, the signal will fall down to 1080p. Lower-grade cabling or incorrect terminations can reduce performance.

Verify the Cat cable run is within 400 ft for 4K operation.
Check the source device resolution settings. Confirm the source is set to 4K@60Hz.
Confirm the display supports 4K.
Use Cat 6 or Cat 7 for best 4K performance; Cat 5e may limit results.
Verify T568B termination on both ends of the Cat cable.
Try changing the HDMI cables.
Confirm if direct connection between source and display works as expected.

4. HDR10+ not passing through

The UHD-EXB400R-K supports HDR, but HDR10+ passthrough may depend on the source, display, and cable quality. In some setups, HDR may pass while HDR10+ does not.

Use a certified High Speed HDMI 2.0 cable between the source and transmitter. Try a HDMI 2.1 cable for best performance.
Confirm the source and display both support HDR10+.
Test with a different source, display, or HDMI cable if available.

5. Audio not passing through

The UHD-EXB400R-K passes audio embedded in the HDMI signal. If audio is missing, the issue is often related to source audio settings, format compatibility, or cable quality.

Check the audio format setting on the media source.
Confirm the display supports the audio format being sent.
Power cycle the system.
If audio works on a short HDMI cable but not through the extender, try changing the CAT cable.
Try using a different media source to rule out a compatibility issue.

6. Unit worked for a period then stopped

Intermittent operation can be caused by power, cable, or heat-related issues. A full reset is the first step.

Unplug both the transmitter and receiver.
Wait 30 seconds before reconnecting power.
Check for loose HDMI or Cat cable connections.
Ensure the units have adequate ventilation and are not exposed to excessive heat.

7. IR control not working

The UHD-EXB400R-K supports bi-directional IR control allowing you to control the media source at the display location or the display from the media source location.

For IR to work properly the connections need to be made correctly. The IR Blaster cable will connect to the IR OUT port on the Transmitter and the IR Receiver cable would connect to the IR IN port on the Receiver unit. Place the IR Receiver cable's head near the front of the TV so it is in line of sight. Use the media source remote (not the TV's) and point to the IR Receiver head and press any button. The signal would travel back over the CAT cable to the Transmitter end and come out the IR Blaster cable. Make sure the IR Blaster head is placed near or on the IR window of the media source device you wish to control.

To control the display, connect the IR Blaster to the IR OUT port on the Receiver unit and place its head on the front of the TV where the TV's IR window is located. On the Transmitter end, connect the IR Receiver cable to the IR IN port and place its head in line of sight so you can point the TV remote to it and control it.

For help with IR connections, refer to this video:

8. CEC not working

CEC passthrough depends on CEC being enabled on every connected device. Brand-specific CEC names may differ.

Enable CEC on the TV and source device.
Samsung uses Anynet+, LG uses SimpLink, and Sony uses Bravia Sync.
Power cycle all connected devices after enabling CEC.
Note that CEC behavior depends on every connected device supporting CEC and having it enabled.
Confirm if CEC works as expected with the media source and display connected directly.

9. Unit not working at all

If the extender is completely unresponsive, isolate the source, display, and cabling before concluding the unit has failed.

Unplug both the transmitter and receiver, wait 30 seconds, and reconnect power.
Test the source directly to the display to confirm the source and HDMI cables are working.
Check all cable connections and try alternate known-good cables where possible.
If the unit remains unresponsive after power cycling and cable checks, contact support.

Contact support

Contact OREI support if the steps in this guide do not resolve the issue. When you reach out, it would be helpful to have some or all of the details mentioned below:

Your setup details, including the source device, display model, cable type, and run length
The problem you are facing and the troubleshooting steps you have already tried
Your purchase invoice or order number
The model numbers for all connected equipment, if possible

Our support team is available via phone or email between 9 AM to 5 PM CST, Monday through Friday.

Email: info@orei.com

Phone: +1 877-290-5530

Disclaimer

This troubleshooting guide is provided for general support purposes only. Results may vary depending on the source device, display, cabling, installation environment, and connected accessories. If you are unsure about any step, or if the issue persists after following this guide, contact OREI support for assistance.

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