Pi4 - No signal to monitor after several days

Help and Support Raspberry Pi
1

Bit of an odd one this.

My OSMC server Pi4 is connected via HDMI to a bog standard 1080p Acer PC monitor.

I very rarely use it, mainly only when I want to use file manager to copy something off the server onto a USB stick because it’s quicker than via my network.

A while ago, after the monitor had been turned off for several days / weeks I started noticing that when I pressed the monitor power button there was no signal. Changing inputs on the monitor did nothing so the Pi 4 needed to be rebooted before the display returned.

I thought I had fixed this by disabling CEC in the OSMC GUI, and specifying the correct HDMI mode and group in config-user.txt, however after trying to turn the monitor on today the same issue has occurred.

Unfortunately as well for some reason my log file was nearly 1 gig in size and notepad++ refuses to open it. I have rebooted and made sure a new log file is now in place and if this happens again I will hopefully be able to upload the logs, but as of now, the monitor can be switched off and on with no issues.

I’ve swapped out the mini HDMI to HDMI cable to try troubleshooting that, are there any low-power / suspend modes or anything else it could be?

2

You might need to hardcode an EDID for the monitor.

If it happens after a period of time it could be a memory leak caused by an add-on or a problem with system stability.

3

I’ve not noticed an issue with system stability as this is my server Pi running the MySQL DB, it always seems to be responsive when streaming to other devices around the house, unless there’s such a thing as just local instability, perhaps backed up by the log being nearly 1GB?

In terms of addons I only have Extras from the Kodi repo installed, but I’ve just disabled it to test.

I’ll try extracting the EDID and see if that helps. I’ve just checked and the display is still active but would it help if I upped the current log just to see if anything stands out?

Thanks!

4

Is the device accessible via SSH when you can’t get a picture?

5

Yes

6

What happens if you do systemctl restart mediacenter? Does the screen come back?

7

Next time it happens I’ll give that a try. Thanks for the assistance.

8

You might also try a different PSU and disabling the screensaver if you have one in use. As for the log if you use Notepad++ it can open text files that are too large for MS Notepad.

9

Will disable screensaver, no spare USB C PSU unfortunately and I was trying to open log in Notepad++. Really surprised, I thought it opened everything!

10

@sam_nazarko Sorry to bug you, I thought I knew how to extract and set the EDID but things seem to have moved on since I last tried it. Do you have a link to an up to date guide please?

11

So I managed to dump the EDID by switching the video driver to FKMS mode, this is the resulting file…

edid-decode (hex):

00 ff ff ff ff ff ff 00 04 72 68 04 71 2b 50 72
19 1b 01 03 80 34 1d 78 2a 2c c5 a4 56 50 a1 28
0f 50 54 b3 0c 00 71 4f 81 80 81 c0 81 00 95 00
b3 00 d1 c0 01 01 02 3a 80 18 71 38 2d 40 58 2c
45 00 09 25 21 00 00 1e 00 00 00 fd 00 37 4c 1e
53 11 00 0a 20 20 20 20 20 20 00 00 00 ff 00 54
33 53 45 45 30 30 35 34 32 30 36 0a 00 00 00 fc
00 41 63 65 72 20 4b 41 32 34 30 48 51 0a 01 30

02 03 1e f1 4b 90 02 03 04 11 12 13 05 14 1f 01
23 09 07 07 83 01 00 00 65 03 0c 00 10 00 02 3a
80 18 71 38 2d 40 58 2c 45 00 09 25 21 00 00 1e
8c 0a d0 8a 20 e0 2d 10 10 3e 96 00 09 25 21 00
00 18 01 1d 00 72 51 d0 1e 20 6e 28 55 00 09 25
21 00 00 1e 8c 0a d0 90 20 40 31 20 0c 40 55 00
09 25 21 00 00 18 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 c9

----------------

Block 0, Base EDID:
  EDID Structure Version & Revision: 1.3
  Vendor & Product Identification:
    Manufacturer: ACR
    Model: 1128
    Serial Number: 1917856625
    Made in: week 25 of 2017
  Basic Display Parameters & Features:
    Digital display
    Maximum image size: 52 cm x 29 cm
    Gamma: 2.20
    DPMS levels: Off
    RGB color display
    First detailed timing is the preferred timing
  Color Characteristics:
    Red  : 0.6406, 0.3378
    Green: 0.3154, 0.6289
    Blue : 0.1591, 0.0585
    White: 0.3134, 0.3291
  Established Timings I & II:
    IBM     :   720x400    70.081663 Hz   9:5     31.467 kHz     28.320000 MHz
    DMT 0x04:   640x480    59.940476 Hz   4:3     31.469 kHz     25.175000 MHz
    Apple   :   640x480    66.666667 Hz   4:3     35.000 kHz     30.240000 MHz
    DMT 0x08:   800x600    56.250000 Hz   4:3     35.156 kHz     36.000000 MHz
    DMT 0x09:   800x600    60.316541 Hz   4:3     37.879 kHz     40.000000 MHz
    DMT 0x10:  1024x768    60.003840 Hz   4:3     48.363 kHz     65.000000 MHz
    DMT 0x11:  1024x768    70.069359 Hz   4:3     56.476 kHz     75.000000 MHz
  Standard Timings:
    DMT 0x15:  1152x864    75.000000 Hz   4:3     67.500 kHz    108.000000 MHz
    DMT 0x23:  1280x1024   60.019740 Hz   5:4     63.981 kHz    108.000000 MHz
    DMT 0x55:  1280x720    60.000000 Hz  16:9     45.000 kHz     74.250000 MHz
    DMT 0x1c:  1280x800    59.810326 Hz  16:10    49.702 kHz     83.500000 MHz
    DMT 0x2f:  1440x900    59.887445 Hz  16:10    55.935 kHz    106.500000 MHz
    DMT 0x3a:  1680x1050   59.954250 Hz  16:10    65.290 kHz    146.250000 MHz
    DMT 0x52:  1920x1080   60.000000 Hz  16:9     67.500 kHz    148.500000 MHz
  Detailed Timing Descriptors:
    DTD 1:  1920x1080   60.000000 Hz  16:9     67.500 kHz    148.500000 MHz (521 mm x 293 mm)
                 Hfront   88 Hsync  44 Hback  148 Hpol P
                 Vfront    4 Vsync   5 Vback   36 Vpol P
    Display Range Limits:
      Monitor ranges (GTF): 55-76 Hz V, 30-83 kHz H, max dotclock 170 MHz
    Display Product Serial Number: 'T3SEE0054206'
    Display Product Name: 'Acer KA240HQ'
  Extension blocks: 1
Checksum: 0x30

----------------

Block 1, CTA-861 Extension Block:
  Revision: 3
  Underscans IT Video Formats by default
  Basic audio support
  Supports YCbCr 4:4:4
  Supports YCbCr 4:2:2
  Native detailed modes: 1
  Video Data Block:
    VIC  16:  1920x1080   60.000000 Hz  16:9     67.500 kHz    148.500000 MHz (native)
    VIC   2:   720x480    59.940060 Hz   4:3     31.469 kHz     27.000000 MHz
    VIC   3:   720x480    59.940060 Hz  16:9     31.469 kHz     27.000000 MHz
    VIC   4:  1280x720    60.000000 Hz  16:9     45.000 kHz     74.250000 MHz
    VIC  17:   720x576    50.000000 Hz   4:3     31.250 kHz     27.000000 MHz
    VIC  18:   720x576    50.000000 Hz  16:9     31.250 kHz     27.000000 MHz
    VIC  19:  1280x720    50.000000 Hz  16:9     37.500 kHz     74.250000 MHz
    VIC   5:  1920x1080i  60.000000 Hz  16:9     33.750 kHz     74.250000 MHz
    VIC  20:  1920x1080i  50.000000 Hz  16:9     28.125 kHz     74.250000 MHz
    VIC  31:  1920x1080   50.000000 Hz  16:9     56.250 kHz    148.500000 MHz
    VIC   1:   640x480    59.940476 Hz   4:3     31.469 kHz     25.175000 MHz
  Audio Data Block:
    Linear PCM:
      Max channels: 2
      Supported sample rates (kHz): 48 44.1 32
      Supported sample sizes (bits): 24 20 16
  Speaker Allocation Data Block:
    FL/FR - Front Left/Right
  Vendor-Specific Data Block (HDMI), OUI 00-0C-03:
    Source physical address: 1.0.0.0
  Detailed Timing Descriptors:
    DTD 2:  1920x1080   60.000000 Hz  16:9     67.500 kHz    148.500000 MHz (521 mm x 293 mm)
                 Hfront   88 Hsync  44 Hback  148 Hpol P
                 Vfront    4 Vsync   5 Vback   36 Vpol P
    DTD 3:   720x480    59.940060 Hz   3:2     31.469 kHz     27.000000 MHz (521 mm x 293 mm)
                 Hfront   16 Hsync  62 Hback   60 Hpol N
                 Vfront    9 Vsync   6 Vback   30 Vpol N
    DTD 4:  1280x720    60.000000 Hz  16:9     45.000 kHz     74.250000 MHz (521 mm x 293 mm)
                 Hfront  110 Hsync  40 Hback  220 Hpol P
                 Vfront    5 Vsync   5 Vback   20 Vpol P
    DTD 5:   720x576    50.000000 Hz   5:4     31.250 kHz     27.000000 MHz (521 mm x 293 mm)
                 Hfront   12 Hsync  64 Hback   68 Hpol N
                 Vfront    5 Vsync   5 Vback   39 Vpol N
Checksum: 0xc9

----------------

Preferred Video Timing if only Block 0 is parsed:
  DTD   1:  1920x1080   60.000000 Hz  16:9     67.500 kHz    148.500000 MHz (521 mm x 293 mm)
                 Hfront   88 Hsync  44 Hback  148 Hpol P
                 Vfront    4 Vsync   5 Vback   36 Vpol P

----------------

Preferred Video Timings if Block 0 and CTA-861 Blocks are parsed:
  DTD   1:  1920x1080   60.000000 Hz  16:9     67.500 kHz    148.500000 MHz (521 mm x 293 mm)
                 Hfront   88 Hsync  44 Hback  148 Hpol P
                 Vfront    4 Vsync   5 Vback   36 Vpol P
  VIC  16:  1920x1080   60.000000 Hz  16:9     67.500 kHz    148.500000 MHz (native)
                 Hfront   88 Hsync  44 Hback  148 Hpol P
                 Vfront    4 Vsync   5 Vback   36 Vpol P

----------------

Native Video Resolution:
  1920x1080

----------------

edid-decode SHA: 84ddf9155376 2021-10-03 10:37:45

Warnings:

Block 1, CTA-861 Extension Block:
  Display Product Serial Number is set, so the Serial Number in the Base EDID should be 0.
EDID:
  CTA-861: Multiple native progressive timings are defined.

Failures:

Block 1, CTA-861 Extension Block:
  Missing VCDB, needed for Set Selectable RGB Quantization to avoid interop issues.
EDID:
  Base EDID: Some timings are out of range of the Monitor Ranges:
    Vertical Freq: 50.000 - 75.000 Hz (Monitor: 55.000 - 76.000 Hz)
    Horizontal Freq: 28.125 - 67.500 kHz (Monitor: 30.000 - 83.000 kHz)

EDID conformity: FAIL

Does this suggest it’s the monitor at fault? Any next steps?

Thanks!

12

If you can get a picture on the monitor at all I think it’s OK

Incorrect timings should and probably are ignored by the Raspberry Pi kernel.

13

OK well I’ve done as advised in this thread, I’ve placed the edid.dat in /boot and specified hdmi_edid_file=1 in config-user.txt

Time will tell I guess. Thanks as always.