Secondary monitor Loses DisplayPort Signal when Daisy Chained to Primary Monitor

Summary: This article provides information about the secondary monitor losing DisplayPort (DP) signal when daisy changed to a primary monitor.

This article applies to This article does not apply to This article is not tied to any specific product. Not all product versions are identified in this article.
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Symptoms

Affected Products:

  • Dell P2422H
  • Dell P2424HEB
  • Dell P2225H
  • Dell P2425HE
  • Dell P2425
  • Dell P2725H
  • Dell E2424HS
  • Dell E2724HS

How to setup to reproduce the issue:

  1. Connect computer using Type C cable to the primary monitor such as P2424HEB.
  2. Using a DP cable, Daisy chain (MST) the primary monitor to the secondary monitor such as the P2422H.

The secondary monitor does not wake up and does not show video when powering up the computer. To recover video on the secondary monitor, unplug the power and plug back in.

Note: This symptom failure rate is low and random.

Cause

There is a functionality issue with the monitor scalar device MT9700.

Resolution

Update the monitor firmware to version:

  • P2425HE firmware version Mxx103 or later
  • P2424HEB firmware version M2T106 or later

To download the monitor firmware, go to the Dell Drivers and Download section for your monitor.

Note: If the problem is present after the firmware has been installed. Power cycle both monitors (disconnect and reconnect the power cable) as the firmware might not work once the monitors are in a no video state.

If there are any concerns or issues, contact Dell Technical support.

Affected Products

Dell P2422H, Dell E2424HS, Dell E2724HS, Dell P2225H, Dell P2424HEB, Dell P2425, Dell P2425H, Dell P2425HE, Dell P2725H
Article Properties
Article Number: 000232329
Article Type: Solution
Last Modified: 14 May 2025
Version:  7
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