Remedy for faulty monitor which fails to respond its capabilities

[CC0126]

At first I only used it to control my AOC Q2790PQ, it had no problems, but after I replaced a monitor AOC Q2790PC, the software did not work properly.
After many searches, I found the open source address of your software, downloaded its source code, and studied it.
After I tested DDC-Control, AOC iMenu, FreeMonitorManager, I found the problem.
This new monitor has multiple interfaces (such as HDMI, DP, USB-C), the VCP value of the USB-C interface returns to normal, but HDMI returns garbled characters, which makes the software unable to obtain whether the display actually supports DDC /CI command, which hinders the work of the software.
I can get the actual brightness by judging that the VCP has a response but cannot be resolved. To determine whether the monitor supports DDC/CI non-standard, just like FreeMonitorManager.
Now he works fine on my monitor.
probe.log is here:

[Date: 2021/12/19 下午 06:12:53 Ver: 3.8.0.0]
{
  "System": "Manufacturer: LENOVO, Model: 80NV",
  "Device Context - DeviceItems": [
    {
      "DeviceInstanceId": "DISPLAY\\AOC2790\\4&1c062684&1&UID198147",
      "Description": "Generic PnP Monitor",
      "DisplayIndex": 1,
      "MonitorIndex": 0
    }
  ],
  "DisplayMonitor - DisplayItems": [
    {
      "DeviceInstanceId": "DISPLAY\\AOC2790\\4&1c062684&1&UID198147",
      "DisplayName": "Q2790R3",
      "IsInternal": false,
      "ConnectionDescription": "HDMI",
      "PhysicalSize": 26.9708023
    }
  ],
  "Display Config - DisplayItems": [
    {
      "DeviceInstanceId": "DISPLAY\\AOC2790\\4&1c062684&1&UID198147",
      "DisplayName": "Q2790R3",
      "IsInternal": false,
      "ConnectionDescription": "HDMI",
      "IsAvailable": true
    }
  ],
  "Device Installation - InstalledItems": [
    {
      "DeviceInstanceId": "DISPLAY\\AOC2790\\4&1C062684&1&UID198147",
      "Description": "通用即插即用监视器",
      "IsRemovable": true
    }
  ],
  "Monitor Configuration - PhysicalItems": [
    {
      "Key": {
        "DisplayIndex": 1,
        "MonitorRect": "Location:0,0, Size:2560,1440"
      },
      "Value": [
        {
          "Description": "Generic PnP Monitor",
          "MonitorIndex": 0,
          "Capability": {
            "IsHighLevelBrightnessSupported": false,
            "IsLowLevelBrightnessSupported": false,
            "IsContrastSupported": false,
            "CapabilitiesString": "O╠",
            "CapabilitiesReport": "Luminance: False, Contrast: False, Speaker Volume: False, Power Mode: False",
            "CapabilitiesData": "T6hkAMzMzMw4AQAAAAAAAAAAAgAu8uk9svQDADOO7T2y9NcBAQAAAAEAAAABAAAABAACAAAAAAAAAAAAAAAAAAIAAAAIAAIAAAAAAAAAAAAAAAAAAAAAAFIAAAAAAAAAUgAAAFwAXAA\/AFwARABJAFMAUABMAEEAWQAjAEEATwBDADIANwA5ADAAIwA0ACYAMQBjADAANgAyADYAOAA0ACYAMQAmAFUASQBEADEAOQA4ADEANAA3ACMAewBlADYAZgAwADcAYgA1AGYALQBlAGUAOQA3AC0ANABhADkAMAAtAGIAMAA3ADYALQAzADMAZgA1ADcAYgBmADQAZQBhAGEANwB9AAAAAgAAAFNYCMrOFqpIsRTenHIzQiMBAAAAAAAAAAAAAABTWAjKzhaqSLEU3pxyM0IjAgAAAAAAAAAAAAAAAAAAAExNRU1IAQAAAAAAAAAAAAA="
          },
          "GetBrightness": "Success: True, Valid: True (Minimum: 0, Current: 0, Maximum: 100)",
          "SetBrightness": "Success: True, Match: True (Expected: 9, Actual: 9)"
        }
      ]
    }
  ],
  "MSMonitorClass - DesktopItems": [
    {
      "DeviceInstanceId": "DISPLAY\\LGD0533\\4&1C062684&1&UID265988",
      "Description": "通用即插即用监视器",
      "BrightnessLevels": "0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100"
    }
  ],
  "ElapsedTime": [
    "DeviceItems    -> 0.001",
    "DisplayMonitorItems -> 0.013",
    "DisplayConfigItems -> 0.007",
    "InstalledItems -> 0.014",
    "PhysicalItems  -> 8.162",
    "DesktopItems   -> 0.035"
  ]
}

[CC0126]

operation.log:
[Date: 2021/12/19 下午 06:12:43 Ver: 3.8.0.0]
Enabled

[emoacht]

Thanks for the explanation.
I understand that you are talking about a monitor which fails to respond to the inquiry for its capabilities by DDC/CI command. Your case looks similar to #215. Damn AOC ... I will call them faulty monitors.

Generally I do not prefer to add modifications which result in extra function calls even in the case of decent monitors. It is undesirable to make the systems which have only decent monitors to use extra resources for the sake of faulty monitors. Thus, I will not merge your PR #269. In addition, if you wish check the functionality of a monitor without the information on its capabilities, you have to test not only getting brightness but also setting brightness both in high and low levels. It will be cumbersome.

Instead, I think if a user is confident that a monitor will work anyway, it will be relatively better to skip testing process alltogether using a white list of such monitors provided by, perhaps, command-line arguments. I am still wondering but this is my initial thoughts.

P.S. To obtain meaningul information from operation.log, you need to use this app for a while.

[CC0126]

Is there any command-line can let the software skip the check of the VCP return codes?
Now I can't use anything on the software it says “can't control the monitor”

[CC0126]

It shows like this. But I opened the DDC/CI function. After I change the code like PR #269 it works well like this:

[CC0126]

The new operation.log is here

[Date: 2021/12/19 下午 06:12:43 Ver: 3.8.0.0]
Enabled

[Date: 2021/12/19 下午 06:12:53 Ver: 3.8.0.0]
ScanAsync [2021/12/19 下午 06:12:48]
{
  "Items": [
    {
      "Type": "UnreachableMonitorItem",
      "DeviceInstanceId": "DISPLAY\AOC2790\4&1c062684&1&UID198147",
      "Description": "Q2790R3",
      "DisplayIndex": 1,
      "MonitorIndex": 0,
      "MonitorRect": Empty,
      "IsReachable": false,
      "IsBrightnessSupported": false,
      "IsContrastSupported": false,
      "Brightness": -1,
      "BrightnessSystemAdjusted": -1,
      "Contrast": -1
    }
  ],
  "Monitors": [
    {
      "Item": {
        "Type": "UnreachableMonitorItem",
        "DeviceInstanceId": "DISPLAY\AOC2790\4&1c062684&1&UID198147",
        "Description": "Q2790R3",
        "DisplayIndex": 1,
        "MonitorIndex": 0,
        "MonitorRect": Empty,
        "IsReachable": false,
        "IsBrightnessSupported": false,
        "IsContrastSupported": false,
        "Brightness": -1,
        "BrightnessSystemAdjusted": -1,
        "Contrast": -1
      },
      "Name": "Q2790R3",
      "IsUnison": true,
      "IsControllable": false,
      "IsConfirmed": false,
      "ControllableCount": 2,
      "IsByKey": false,
      "IsSelected": false,
      "IsTarget": true
    }
  ]
}

[Date: 2021/12/19 下午 06:13:13 Ver: 3.8.0.0]
OnMonitorAccessFailed
Status: Failed
Message: 

[Date: 2021/12/19 下午 11:18:28 Ver: 3.8.0.0]
Initiated

[Date: 2021/12/19 下午 11:18:31 Ver: 3.8.0.0]
Check update: No update

[Date: 2021/12/19 下午 11:18:34 Ver: 3.8.0.0]
ScanAsync [2021/12/19 下午 11:18:29]
{
  "Items": [
    {
      "Type": "UnreachableMonitorItem",
      "DeviceInstanceId": "DISPLAY\AOC2790\4&1c062684&1&UID198147",
      "Description": "Q2790R3",
      "DisplayIndex": 1,
      "MonitorIndex": 0,
      "MonitorRect": Empty,
      "IsReachable": false,
      "IsBrightnessSupported": false,
      "IsContrastSupported": false,
      "Brightness": -1,
      "BrightnessSystemAdjusted": -1,
      "Contrast": -1
    }
  ],
  "Monitors": [
    {
      "Item": {
        "Type": "UnreachableMonitorItem",
        "DeviceInstanceId": "DISPLAY\AOC2790\4&1c062684&1&UID198147",
        "Description": "Q2790R3",
        "DisplayIndex": 1,
        "MonitorIndex": 0,
        "MonitorRect": Empty,
        "IsReachable": false,
        "IsBrightnessSupported": false,
        "IsContrastSupported": false,
        "Brightness": -1,
        "BrightnessSystemAdjusted": -1,
        "Contrast": -1
      },
      "Name": "Q2790R3",
      "IsUnison": true,
      "IsControllable": false,
      "IsConfirmed": false,
      "ControllableCount": 3,
      "IsByKey": false,
      "IsSelected": false,
      "IsTarget": true
    }
  ]
}

[Date: 2021/12/19 下午 11:19:16 Ver: 3.8.0.0]
OnMonitorAccessFailed
Status: Failed
Message: 

[Date: 2021/12/20 下午 07:28:09 Ver: 3.8.0.0]
Initiated

[Date: 2021/12/20 下午 07:28:10 Ver: 3.8.0.0]
Check update: Failed
System.Exception: 异常来自 HRESULT:0x8024402C
   在 System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   在 System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   在 StoreAgency.StoreAgent.<CheckUpdateAsync>d__43.MoveNext()

[Date: 2021/12/20 下午 07:28:13 Ver: 3.8.0.0]
ScanAsync [2021/12/20 下午 07:28:10]
{
  "Items": [
    {
      "Type": "UnreachableMonitorItem",
      "DeviceInstanceId": "DISPLAY\AOC2790\4&1c062684&1&UID198147",
      "Description": "Q2790R3",
      "DisplayIndex": 1,
      "MonitorIndex": 0,
      "MonitorRect": Empty,
      "IsReachable": false,
      "IsBrightnessSupported": false,
      "IsContrastSupported": false,
      "Brightness": -1,
      "BrightnessSystemAdjusted": -1,
      "Contrast": -1
    }
  ],
  "Monitors": [
    {
      "Item": {
        "Type": "UnreachableMonitorItem",
        "DeviceInstanceId": "DISPLAY\AOC2790\4&1c062684&1&UID198147",
        "Description": "Q2790R3",
        "DisplayIndex": 1,
        "MonitorIndex": 0,
        "MonitorRect": Empty,
        "IsReachable": false,
        "IsBrightnessSupported": false,
        "IsContrastSupported": false,
        "Brightness": -1,
        "BrightnessSystemAdjusted": -1,
        "Contrast": -1
      },
      "Name": "Q2790R3",
      "IsUnison": false,
      "IsControllable": false,
      "IsConfirmed": false,
      "ControllableCount": 3,
      "IsByKey": false,
      "IsSelected": false,
      "IsTarget": true
    }
  ]
}

[Date: 2021/12/20 下午 07:28:15 Ver: 3.8.0.0]
OnMonitorAccessFailed
Status: Failed
Message: 

[Date: 2021/12/20 下午 07:28:17 Ver: 3.8.0.0]
OnMonitorAccessFailed
Status: Failed
Message: 

[Date: 2021/12/20 下午 07:28:18 Ver: 3.8.0.0]
OnMonitorAccessFailed
Status: Failed
Message: 

[Date: 2021/12/20 下午 07:31:43 Ver: 3.8.0.0]
Initiated

[Date: 2021/12/20 下午 07:31:46 Ver: 3.8.0.0]
Check update: No update

[Date: 2021/12/20 下午 07:31:47 Ver: 3.8.0.0]
ScanAsync [2021/12/20 下午 07:31:43]
{
  "Items": [
    {
      "Type": "UnreachableMonitorItem",
      "DeviceInstanceId": "DISPLAY\AOC2790\4&1c062684&1&UID198147",
      "Description": "Q2790R3",
      "DisplayIndex": 1,
      "MonitorIndex": 0,
      "MonitorRect": Empty,
      "IsReachable": false,
      "IsBrightnessSupported": false,
      "IsContrastSupported": false,
      "Brightness": -1,
      "BrightnessSystemAdjusted": -1,
      "Contrast": -1
    }
  ],
  "Monitors": [
    {
      "Item": {
        "Type": "UnreachableMonitorItem",
        "DeviceInstanceId": "DISPLAY\AOC2790\4&1c062684&1&UID198147",
        "Description": "Q2790R3",
        "DisplayIndex": 1,
        "MonitorIndex": 0,
        "MonitorRect": Empty,
        "IsReachable": false,
        "IsBrightnessSupported": false,
        "IsContrastSupported": false,
        "Brightness": -1,
        "BrightnessSystemAdjusted": -1,
        "Contrast": -1
      },
      "Name": "Q2790R3",
      "IsUnison": false,
      "IsControllable": false,
      "IsConfirmed": false,
      "ControllableCount": 3,
      "IsByKey": false,
      "IsSelected": false,
      "IsTarget": true
    }
  ]
}

[Date: 2021/12/20 下午 07:31:51 Ver: 3.8.0.0]
OnMonitorAccessFailed
Status: Failed
Message: 

[Date: 2021/12/20 下午 07:31:53 Ver: 3.8.0.0]
OnMonitorAccessFailed
Status: Failed
Message: 

[Date: 2021/12/20 下午 07:31:53 Ver: 3.8.0.0]
OnMonitorAccessFailed
Status: Failed
Message: 

[Date: 2021/12/20 下午 07:31:54 Ver: 3.8.0.0]
OnMonitorAccessFailed
Status: Failed
Message: 

[Date: 2021/12/20 下午 07:31:54 Ver: 3.8.0.0]
OnMonitorAccessFailed
Status: Failed
Message: 

[Date: 2021/12/20 下午 07:32:03 Ver: 3.8.0.0]
OnMonitorAccessFailed
Status: Failed
Message: 

[Date: 2021/12/20 下午 07:32:04 Ver: 3.8.0.0]
OnMonitorAccessFailed
Status: Failed
Message: 

[emoacht]

Is there any command-line can let the software skip the check of the VCP return codes?

No, not yet.

[CC0126]

I think it is possible to add an option or command to the hidden menu. If the user thinks his monitor is okay, he can try it. There may be more Monitors with such problems, and the returned VCP data may change frequently, so it may take a lot of effort to design a whitelist.

[emoacht]

In fact, a whitelist by command-line option is the least costly approach.

Added preclear option by 6e5d4a7 and 1f0d50a
To use this option,

1. Get probe.log and find the Device Instance ID of the monitor in question.
2. Use this option as shown below. If there are multiple monitors in question, continue Device Instance ID delimited by space.

/preclear [Device Instance ID]

3. You can use command-line arguments in the hidden menu to set this option.

In case you have multiple monitors, simply add thier Device Instance IDs.

/preclear [First Device Instance ID] [Second Device Instance ID]

[CC0126]

Thank you very much! I downloaded the latest code and test the "preclear" commandline. It now works well!
Will you release these change in the next version on the Microsoft Store?

[emoacht]

Thanks for the confirmation.
This preclear option is now included in Ver 3.8.2.
I will keep this issue pinned as the notice of this option.

[HaiyiMei]

Hi there. I've got the same issue like here.

[Date: 2021-12-24 13:20:49 Ver: 3.8.2.0]
ScanAsync [2021-12-24 13:20:49]
{
  "Items": [
    {
      "Type": "UnreachableMonitorItem",
      "DeviceInstanceId": "DISPLAY\PHLC216\5&1015af17&0&UID8448",
      "Description": "PHL 276C8",
      "DisplayIndex": 1,
      "MonitorIndex": 0,
      "MonitorRect": Empty,
      "IsReachable": false,
      "IsBrightnessSupported": false,
      "IsContrastSupported": false,
      "IsPrecleared": false,
      "Brightness": -1,
      "BrightnessSystemAdjusted": -1,
      "Contrast": -1
    }
  ],
  "Monitors": [
    {
      "Item": {
        "Type": "UnreachableMonitorItem",
        "DeviceInstanceId": "DISPLAY\PHLC216\5&1015af17&0&UID8448",
        "Description": "PHL 276C8",
        "DisplayIndex": 1,
        "MonitorIndex": 0,
        "MonitorRect": Empty,
        "IsReachable": false,
        "IsBrightnessSupported": false,
        "IsContrastSupported": false,
        "IsPrecleared": false,
        "Brightness": -1,
        "BrightnessSystemAdjusted": -1,
        "Contrast": -1
      },
      "Name": "PHL 276C8",
      "IsUnison": false,
      "IsControllable": false,
      "IsConfirmed": false,
      "ControllableCount": 2,
      "IsByKey": false,
      "IsSelected": false,
      "IsTarget": true
    }
  ]
}

[Date: 2021-12-24 13:20:54 Ver: 3.8.2.0]
OnMonitorAccessFailed
Status: Failed
Message: 

[Date: 2021-12-24 13:20:54 Ver: 3.8.2.0]
OnMonitorAccessFailed
Status: Failed
Message: 

And I did the same action as here

In fact, a whitelist by command-line option is the least costly approach.

Added preclear option by 6e5d4a7 and 1f0d50a To use this option,

1. Get probe.log and find the Device Instance ID of the monitor in question.
2. Use this option as shown below. If there are multiple monitors in question, continue Device Instance ID delimited by space.

/preclear [Device Instance ID]

3. You can use command-line arguments in the hidden menu to set this option.

And I got this new log:

[Date: 2021-12-24 13:23:09 Ver: 3.8.2.0]
Initiated

[Date: 2021-12-24 13:23:10 Ver: 3.8.2.0]
OnMonitorAccessFailed
Status: TransmissionFailed
Message: Low level, Code: -1071241854, Message: An error occurred while transmitting data to the device on the I2C bus.


[Date: 2021-12-24 13:23:10 Ver: 3.8.2.0]
ScanAsync [2021-12-24 13:23:10]
{
  "Items": [
    {
      "Type": "DdcMonitorItem",
      "DeviceInstanceId": "DISPLAY\PHLC216\5&1015af17&0&UID8448",
      "Description": "PHL 276C8",
      "DisplayIndex": 1,
      "MonitorIndex": 0,
      "MonitorRect": 0,0,2560,1440,
      "IsReachable": true,
      "IsBrightnessSupported": true,
      "IsContrastSupported": true,
      "IsPrecleared": true,
      "Brightness": -1,
      "BrightnessSystemAdjusted": -1,
      "Contrast": -1
    }
  ],
  "Monitors": [
    {
      "Item": {
        "Type": "DdcMonitorItem",
        "DeviceInstanceId": "DISPLAY\PHLC216\5&1015af17&0&UID8448",
        "Description": "PHL 276C8",
        "DisplayIndex": 1,
        "MonitorIndex": 0,
        "MonitorRect": 0,0,2560,1440,
        "IsReachable": true,
        "IsBrightnessSupported": true,
        "IsContrastSupported": true,
        "IsPrecleared": true,
        "Brightness": -1,
        "BrightnessSystemAdjusted": -1,
        "Contrast": -1
      },
      "Name": "PHL 276C8",
      "IsUnison": false,
      "IsControllable": true,
      "IsConfirmed": false,
      "ControllableCount": 2,
      "IsByKey": false,
      "IsSelected": false,
      "IsTarget": false
    }
  ]
}

And I got nothing in my Monitorian software:

@emoacht @CC0126 Do you know why this happens? Thanks a lot.

[emoacht]

@HaiyiMei Could you show probe.log?