Need advice (screen not showing output)

Hello all,

I’ve had my console since August. I bought it used from a fellow forum member. It has worked phenomenally. I decided to update my is to take advantage of @Rex repository. My model cm4 has the emmc so I had to remove it to flash it with an I0 board (official raspi io board) when I successfully flashed the emmc I put it all back together. I’d get a backlight but no output on the screen, I did check that devterm was commented out. I reseated everything several times. I found on the uconsole and on the io board I’d get what appeared to be a secondary monitor screen but I had no task bar nor could I get right click to do anything. So I redownloaded and reflashed bookworm with the same result (still checking that devterm was commented out and uconsole was not). I tried the lite with the same result. Finally I stooped to download the clockwork os and flashed it. No change. That was last night, I gave up at 230am. I’ve had the device completely apart and reseated everything 3 times tonight. No change at all…

So, I lay it all at your feet. I’ve done what I can and am at the end of my troubleshooting creativity. At this point I wonder if I have damaged something, but I don’t know what. The HDMI output leaves me kinda hopeful even thought it doesn’t give me the main screen.

Any and all advice welcomed.

Thanks in advance.

After you flash the image in the IO Board are you trying to boot in the IO Board or in the uConsole?
Are you giving it some time to boot first boot can take a minute.

Boot from uconsole first, giving plenty of time for first boot activities.

Does the terminal scare you? Are you able to login to another TTY? (Ctrl+Alt+function key)

No, if I know what to look for, I do okay in the terminal. I’ve got to get some sleep (I work 12 hours graveyard shifts). But if you can help me know what to look for, I’d be willing to take a stab at it.

I got a chance to try it. No change.

Neat, then you are still able to access your computer, but only through a terminal. I guess what’s left to do is to perform diagnostics to figure out why your screen isn’t coming to life. Logs? config’s? You may want to share more relevant information so somebody can help.

Okay. I am this far. What logs need to be pulled up to get an idea where the failure is?

k, like I said I got this far. I changed directory to /boot. opened nano at /boot/config.txt had no entries for the uconsole, that and the devterm lines were not commented out… as this is the clockwork os I first commented out the devterm lines and restarted. this took my screen from having a backlight to no backlight at all. so… I am gonna reflash @Rex bookworm and try all this again. perhaps I am on the verge of a breakthrough.

Back on bookworm. Devterm commented out. Any idea what logs should be checked?

Also I’ll note that Iam getting another display other than HDMI (pictured below)

I still have the backlight on the display panel. I can dim and brighten it with the keyboard.

the second display (dsi-1) is the uconsole’s screen. it sounds like you have a bad panel, the backlight is working but no picture.

That could be. I just wonder how pulling the cm4 to flash the emmc killed the panel.

did you take the batteries out when you removed the cm4?

I did, I’ve been really careful about that.

i’d see if you can order just a screen and try that.

I’ll look into it. Thanks. Btw your bookworm os is the best.

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well, its back up. Long story short it wasn’t the screen, it ended up being a main board. thanks for your time and help before. (i bought a new one off ali express and swapped the mother board and scored a black front) now I have some parts. on a separate note: @Rex do I need to reflash the bookworm? (its been updated through apt-get and sits at 6.6.63 v8) I wasn’t sure if the new kernel changes after cm5 release would be included in regular updates.