Hello,

We are facing problem on 13.3" Wavehsare DSI Display.

We have been running 4K video playback while simultaneously monitoring the processor temperature.

During this testing, we have observed a recurring display instability issue, detailed below.

**Observations:**

1. After extended operation, the display begins to flicker, showing only a black screen, wherein Processor temperature is
around 57 °C .

2. Despite the display going black, audio playback normally continues in the background, indicating that video processing itself was not interrupted.

3. Upon restarting the Panel PC, the display becomes visible again but with a whitish discoloration appearing at the corners of the screen.

4. After some additional time, the display returns to normal and the whitish discoloration disappears on its own.


This issue has been reproduced 4–5 times.

- There is no consistent or predictable time interval between occurrences.

- The defect appears intermittently during testing.

If the problem would have been with processor then the performance would been affected.

What could be other possible reasons & how to identify.

 

try adding cooling, it could be the system is over heating, and throttling back its speed to cool itself , and dropping threads.
audio / video algorithums are time critical, they cant wait.. they prioratise audio, dropping video packets if no more time is available in a frame.

two reason.
the human eye is very tollerant of stuttering video , but the ear is not good with stuttering audio,
audio takes lot lass processing so is done when not eniught time fir the video,

 

you did not confirm if the problem is with monitor itself or with source of signal or what is the type of signal source. but whatever the signal source is, it is likely some advanced computing unit, such as raspberry pi, PC or similar. all of those generate video signal using more than just a processor - there will be bunch of ICs and they all need to stay cool. seeing one of them (CPU) getting blistering hot is a clear sign that unit is overheating. there are kits for each of the platforms. adding passive cooling is a bare minimum. if this is not enough, switch to active cooling (forced air circulation).

 

you did not confirm if the problem is with monitor itself or with source of signal or what is the type of signal source. but whatever the signal source is, it is likely some advanced computing unit, such as raspberry pi, PC or similar. all of those generate video signal using more than just a processor - there will be bunch of ICs and they all need to stay cool. seeing one of them (CPU) getting blistering hot is a clear sign that unit is overheating. there are kits for each of the platforms. adding passive cooling is a bare minimum. if this is not enough, switch to active cooling (forced air circulation).

Thank you for your response.

At this stage, we are unable to conclusively determine whether the issue lies with the monitor itself. We would like to better understand the possible causes of this behavior.

From our side, we are using [CM5 ] with [DSI interface].
We have been running 4K video playback while simultaneously monitoring the processor temperature.
We are already using All in one cooling fan for Raspberry pi & we observed Processor temperature does not go above 60 °C when Display is Flickering.

Despite the display going black, audio playback normally continues in the background, indicating that video processing itself was not interrupted.

We would like to have your inputs on potential reasons for such an issue and any recommended checks or diagnostics we can perform to identify the root cause.


For Dis

 

Thank you for your response.

At this stage, we are unable to conclusively determine whether the issue lies with the monitor itself. We would like to better understand the possible causes of this behavior.

From our side, we are using [CM5 ] with [DSI interface].
We have been running 4K video playback while simultaneously monitoring the processor temperature.
We are already using All in one cooling fan for Raspberry pi & we observed Processor temperature does not go above 60 °C when Display is Flickering.

Despite the display going black, audio playback normally continues in the background, indicating that video processing itself was not interrupted.

We would like to have your inputs on potential reasons for such an issue and any recommended checks or diagnostics we can perform to identify the root cause.


For Dis

re what you can imply from audio works, video flickeres
thats how the app works under load,
audio is prioratised , as disrupted audio is more anoying than dispupted video.

 

Hello,

Thanks for the explanation.

However, we would like to better understand how to identify when the application/system is actually under such stress conditions.

Could you please clarify:

• What parameters indicate that the system is under load (e.g., CPU usage, GPU usage, memory utilisation, bandwidth)?
• Are there any threshold values beyond which this behaviour (video flicker) is expected?
• Is there a recommended method or tool to monitor these parameters in real time?
• Can this behaviour be reproduced under defined test conditions?

This will help us verify whether the observed issue is due to system load or something else.

 

re what you can imply from audio works, video flickeres
thats how the app works under load,
audio is prioratised , as disrupted audio is more anoying than dispupted video.

Hello,

Thanks for the explanation.

However, we would like to better understand how to identify when the application/system is actually under such stress conditions.

Could you please clarify:

• What parameters indicate that the system is under load (e.g., CPU usage, GPU usage, memory utilisation, bandwidth)?
• Are there any threshold values beyond which this behaviour (video flicker) is expected?
• Is there a recommended method or tool to monitor these parameters in real time?
• Can this behaviour be reproduced under defined test conditions?

This will help us verify whether the observed issue is due to system load or something else.

 

Hello,

Thanks for the explanation.

However, we would like to better understand how to identify when the application/system is actually under such stress conditions.

Could you please clarify:

• What parameters indicate that the system is under load (e.g., CPU usage, GPU usage, memory utilisation, bandwidth)?
• Are there any threshold values beyond which this behaviour (video flicker) is expected?
• Is there a recommended method or tool to monitor these parameters in real time?
• Can this behaviour be reproduced under defined test conditions?

This will help us verify whether the observed issue is due to system load or something else.

Your asking how to debug a software system
The first thing is what's your OS , what's your experteese level , what's your time scales , what people locally do you have to chat with , what test equipment do you have , what is your level of exoerteese with the test equipment.

 

We are using Raspberry Pi OS (64-bit) on our platform.

Our team comprises both software and hardware design engineers, and we have carried out runtime monitoring during the occurrence of the display flickering issue.We monitored CPU all-core performance via terminal-based tools while the issue was active.But we were not able to interpret the report. However, we were unable to interpret the observed data conclusively.

Additionally, we were unable to log or capture the data during those events. Additionally, the issue is intermittent and does not follow a predictable pattern

We will attempt to capture & share the report when the issue occurs again.

 

Your asking how to debug a software system
The first thing is what's your OS , what's your experteese level , what's your time scales , what people locally do you have to chat with , what test equipment do you have , what is your level of exoerteese with the test equipment.

We are using Raspberry Pi OS (64-bit) on our platform.

Our team comprises both software and hardware design engineers, and we have carried out runtime monitoring during the occurrence of the display flickering issue.We monitored CPU all-core performance via terminal-based tools while the issue was active.But we were not able to interpret the report. However, we were unable to interpret the observed data conclusively.

Additionally, we were unable to log or capture the data during those events. Additionally, the issue is intermittent and does not follow a predictable pattern

We will attempt to capture & share the report when the issue occurs again.

 

if you want others to spend time helping you, stop repeating yourself and try to spend time defining the setup. you still did not even begin to explain used hardware... or software... or configuration.

We are using Raspberry Pi OS (64-bit) on our platform.

what the heck is "our platform"? Raspberry Pi 3, 4, 5, and Zero 2 W or VM or something else? what is the CPU, clock rate, RAM? what are used resources? what are free resources?
did you put large heatsinks on it? did you add cooling fan? if the hardware is not cooled it will throttle speed and results are going to be hard to miss.

Our team comprises both software and hardware design engineers...

so you have a team of engineers but don't have a single spare monitor? your entire team is waiting for their turn to work on this one unit? you have no other monitor to connect to PI (or connect PI monitor to a PC)? are you kidding me?

we have carried out runtime monitoring during the occurrence of the display flickering issue. We monitored CPU all-core performance via terminal-based tools while the issue was active.But we were not able to interpret the report. However, we were unable to interpret the observed data conclusively.

so your team of engineers cannot interpret their own logs? we cannot either... because nobody but your team has seen them.

Additionally, we were unable to log or capture the data during those events. Additionally, the issue is intermittent and does not follow a predictable pattern

how fast is your data capture? what are you capturing? what is the pattern? does anyone on your team have camera or cell phone? can you take a video of the issue? and some pictures of setup? what is ambient temperature? putting heatsink may not work in place that is 45degC, of course the hardware will internally reach even higher temperatures. you can try to focus localized cooling using spray:


the other option is to add heat to specific ICs or parts of the board. if adding heat makes the problem appear sooner and last longer you found the spot. do not burn the board just increase temperature gradually to see where the problem is. you can use hair dryer as well - just to confirm it is the PI or monitor. but to deliver heat to small area (pinpoint problem) consider using something with smaller nozzle:

 

that was some things that could be tried to troubleshoot hardware. but more can be done to test software. for example video takes a lot more space than audio. what if the problem is with memory? did you run any tests to check the resources such as CPU, memory..?