4 in 2 out Display issues.

Dstrong

March 18, 2026 12:33

I have a Samsung Odyssey G9 monitor using PIP/PBP display mode. My original setup used a TESmart 2‑in 2‑out KVM purchased directly from TESmart, and that unit works perfectly.

Recently, I purchased the TESmart HKS402‑P24 (4‑in 2‑out) KVM through Amazon. On both the original unit and the replacement Amazon sent, HDMI Output B does not produce any picture. HDMI Output A works normally.

I tested multiple HDMI cables—including the same cable that works on Output A—and I also connected the monitor directly to HDMI A and HDMI B on the KVM. Only HDMI A ever displays an image.

Since this issue occurred on two separate units, I want to confirm whether there are any settings required to activate the second HDMI output, or if both outputs should function automatically as they do on my 2‑in 2‑out TESmart KVM.

I have a higher‑end TESmart KVM arriving tomorrow (HDMI 2.1 & DP 1.4 Dual 4K144Hz KVM, . Before it arrives, I want to be sure I won’t run into the same issue with Output B. If there are any configuration steps required for dual‑output operation, please advise.

Thank you for your help in resolving this.

0

• Official comment

  

  TESmart.01

  April 14, 2026 08:26

  Dear Customer,

  Thank you for contacting TESmart Support, and thank you for providing the detailed troubleshooting information.

  Based on your description, this issue is most likely related to the video input connection method rather than a fault with HDMI Output B itself.

  The HKS402-P24 is a dual-monitor KVM switch, which means that for both HDMI Output A and HDMI Output B to display normally, the selected computer must provide two independent video input signals to the KVM. In other words, Output B is not a duplicated or mirrored copy of Output A.

  If only one HDMI video input from the computer is connected to the KVM, HDMI Output A may work normally while HDMI Output B remains blank, because there is no second video source assigned to that output path.

  Under normal operation, both outputs should function automatically. There is no separate setting required to manually enable HDMI Output B. However, this depends on the KVM receiving both required video input paths from the selected computer.

  To help confirm this, we recommend checking the following:

  1. Please verify that each connected computer is connected to the KVM with two video cables, corresponding to the two display output paths.
  2. Please confirm that the source device itself supports two active external display outputs at the same time.
  3. If the monitor is being used in PIP/PBP mode, please make sure the monitor is receiving two separate active input signals, rather than only one signal path from the source device.

  If the source device is only sending one active display signal, then the second output on the KVM will also remain blank, even if the KVM itself is functioning normally.

  The same principle will apply to the higher-end dual-monitor KVM you have arriving tomorrow. Dual-output operation does not require a special activation setting, but it does require that the source side provide the corresponding dual video inputs.

  If you would like, you may also send us a photo of the current rear-panel wiring for both the computer side and the monitor side, and we will be happy to help confirm whether the connections are correct.

  Best regards,
  TESmart Technical Support

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