Only Android images work on eMMC (Edge-V)

Okay no other fat cables pushing against the HDMI? Did you attempt to use a different HDMI cable?

If all of the above is true / tried out, then its quite certain to be an issue with the onboard GPU, or some other sub-system related to the HDMI output.

1 Like

Yes I tried a 4k HDMI, too


This is what I’m seeing after it returns from power saver.
This is what happens during shutdown from either eMMC or SDcard. Notice the bottom half is okay, once lightdm has unloaded.

That’s odd. So the HDMI issue is intermittent?

Actually, it is very predictable. But, ~50% of the time, it will only be green instead of the multiple colored squares during startup, probably depending upon whether it is warmed up.
After ~15 minutes, the power saver blanks the screen, so I can move the mouse and everything looks and behaves normally.

That’s very odd. Just out of curiosity, do you have another screen lying around?

Only a 7" Raspberry Pi Touchscreen. I’m on it, but I need to untie cables and restart the EDGE-V. Could be a while, if I have to wait for the power saver. We’ll see.

Well no harm giving that a try too. Because if it is a hardware issue, the issue would (most of the time) be persistent.

Powered on fine. I’m at login. But, that won’t work for me. The touchscreen is for a Raspberry Pi project.

And the RPi screen is connected via MIPI-DSI and TP, and not over HDMI?

No. It’s connected to the same HDMI. BTW, the other monitor is a 50" Toshiba FireTV. I’ve use several other SBCs on it, including ROCK Pi 4, RPi 3B+, and RPi 4B+

Ok, the issue is unlikely with the Edge-V’s GPU. Could you play around with it in the “Rpi screen mode” for a while longer, and see if the fuzzy green squares appear again?

It’s not that we wouldn’t want to exchange your board, its just that you know the 2-way shipping will take a very long time, and be inconvenient for you.

Yeah, but I’ve already waited 3 weeks, just to get to this point. I’ve spent several hundred $ on the ROCK Pi POS. I really need to have the EDGE-V fully functional. Don’t mean to be difficult. But, I’m in no hurry.

Okay I understand. What is the resolution of the Rpi screen? The 50" Toshiba is 4K right?

Ithink it is 1080 x 720, if I remember corectly. Yes, the Toshiba is 4K. I purchased it specifically for the EDGE-V.

Okay play around with both the 4K and 720P displays for a bit, going from one to the other, and see if the issue recurs. I’ll ask @kenny for his feedback when he is available.

I’ve got a USB-C to HDMI adapter cable. Should I be able to use both outputs at the same time? Been wanting to try that.:thinking:
Ha! But, there is no panel and the debian swirl is off center on the touchscreen. Gotta mess with the resolution. But, let me try rebooting. Perhaps the DP works OK.
Looks like the DP is working normally. The HDMI isn’t connected and I moved the Toshiba FireTV to the DP.
The maximum resolution available on the DP is 1920 x 1080
But HDMI allows 3840 x 2160 @ 30 fps
HDMI behaves okay, as long as the DP is connected, too. With both outputs connected to different HDMI inputs on the Toshiba, The HDMI output is still 3840 x 2160, but the DP output is still only 1920 x 1080 (with no panel, so it’s pretty unusable)
YouTube videos on HDMI are very choppy, even @ 720p

Yes, see Edge-V, top, component 4. That USB-C port has Display Port v1.2 output.

BTW, while searching for file format info, I saw that your Beginner’s Guide is alive and on line. It looks great. Congratulations!:call_me_hand:
Have you spoken to Kenny, yet? It’s 3:00 am here.:sleeping:
I’ll get back to you tomorrow.
Thanks a lot for your time.

1 Like
  • YouTube being choppy on RK3399 + Ubuntu + 4K is normal. On 1080P it should run more smoothly, but then again depends on what you have going on in the background, how many windows opened, etc.
  • This does not make sense: HDMI behaves okay, as long as the DP is connected, too.

  • Neither does this: (with no panel, so it’s pretty unusable)

Overall this does not seem like a GPU issue. With a GPU issue, you would persistently experience the problem across HDMI, DP, Rpi screen, etc.

I recommend:

  • Making sure the RK3399 is getting adequate cooling, on Ubuntu it will get hot really fast, and throttle, decreasing the performance. 28nm chips get really hot.

  • Running Android on your Edge-V, and seeing if those green square things re-appear

Usually thermal issues are the inconsistent ones because it takes time before your board builds up sufficient heat to go delirious. Therefore, during testing you would mysteriously find that your problems have gone away…only to have them resurface during normal usage. Note that in my video, my Edge-V was running naked in winter-time temperatures of 25C ambient - whilst your Edge-V is cased-up in the DIY Case (which is better for a lightweight operating system such as Android)

Thank you for your reply. However, none of these issues address the initial problem of the HDMI output being out of sync until the power saver blanks the screen during startup and shutdown, as indicated in my photos. We have already determined that this is not due to a ‘bug’ in the dtb, because other EDGE-V SBCs do not exhibit any problems.
Granted, while working on this, it was discovered that this problem does not happen if the USB-C port is also being used. However, it is not an acceptable workaround to require a both outputs to be connected, just to have HDMI. Clearly, this SBC has defective hardware. I agree that it is difficult to make sense of this behavior. But, I am not an engineer. I’m sure that Khadas would never intentionally sell defective products, which makes it important for engineers to examine and investigate the cause of this defect, whether it is due to a individual component or contamination during the SMC assembly.
Considering that I have invested ~$220 in the EDGE-V and accessories, I think it is only reasonable to have a fully functional product. All things considered, I would like to request instructions for exchanging this defective product with a replacement.
Thank you😎