fos/4 Fixtures Lock Up or Become Unresponsive

Fixtures affected

Can occur on any fixture with an iMX processor:

• ColorSource CPU2 and CPU3
• ColorSource V
• ColorSource Fresnel V
• Source Four LED Series 3
• fos/4 CPU2 (post 2024-07)
• Desire Fresnel CPU2 (post 2022-04)

Symptoms

• Presentation 1: When quickly cycling power to the fixture (i.e. disconnecting power and reconnecting it within 20 seconds), fixture screen goes black and fixture becomes totally unresponsive while running fan at full speed. Power cycling fixture again resolves the issue.
• Presentation 2: While fixture is in use, output suddenly drops to zero, fixture screen goes black and fixture becomes unresponsive while running fan at full speed. Power cycling fixture resolves the issue.

Description

This issue is caused by the 3.3V rail to the iMX processor dropping below a critical level. The processor restarts, but fails to execute the application code bootloader, leaving the CPU in a "limbo" state. Thus, even when the 3.3V rail returns to nominal voltage, the CPU can't recover until the entire fixture is restarted.

The 3.3V rail undervoltage can be caused by a fast power cycle (<20 seconds), because this is not enough time for the PSU capacitors to drain fully. When power is reapplied in this window, there may be enough residual charge in the caps to start the CPU into its "limbo" state. When power cycling any fixture, 20 seconds should always be allowed for the caps to drain before reapplying power.

External power events can also cause the 3.3V rail to drop for the same reason. In some cases, we have seen issues within the power supply provoke this issue as well. Research is still ongoing on that front.

See this article for more general information about the iMX 3.3V lockup issue.

Fix

The issue is usually caused by site power conditions. If this can be ruled out, the power supply should be replaced.

Fixtures affected

Can occur on any fixture with a Multiverse radio:

• ColorSource V
• fos/4
• Desire Fresnel
• S4 LED Series 3

Symptoms

• Presentation 1: While using Multiverse for control, fixture suddenly stops responding to control and may indicate "no signal" behavior (i.e. DMX address flashing on ColorSource fixtures). Other fixtures in the rig do not lose signal. Power cycling fixture restores control.
• Presentation 2: While using Multiverse for control, output suddenly drops to zero, fixture screen goes black and fixture becomes unresponsive while running fan at full speed. Other fixtures in the rig are unaffected. Power cycling fixture resolves the issue.

Description

This issue is caused when the Multiverse radio loses connection with the transmitter, which in some cases can cause the fixture's internal communication bus to enter an infinite loop, resulting in a fixture lockup.

Fix

This issue was fixed in ColorSource V software version 4.1.2 and S4 LED Series 3 software version 1.3.0. These builds prevent the internal communication bus from entering an infinite loop if the radio becomes unresponsive.

Separately, City Theatrical has released new Multiverse radio firmware that should reduce the likelihood of a radio becoming unresponsive in the first place. See this article for more information.

Fixtures affected

Can only occur on ColorSource Spot V and VXT.

Symptoms

• Presentation 1: Output suddenly drops to zero, fixture screen goes black and fixture becomes unresponsive while running fan at full speed. Power cycling fixture does not resolve the issue.
• Presentation 2: Fixture is unable to output one or more colors on its array, via either local control or DMX/Multiverse control. Power cycling fixture does not resolve the issue.

Description

This issue is caused by the ribbon cable between the control card and array becoming loose or unseated.

Fix

Reseat the ribbon cable on the control card side per the instructions in this article.