External portable display not detected by the Pocket Reform

MNT Pocket Reform
1

Hi everyone! I got my Pocket Reform a while ago and I’m very happy with. But I’m having an issue with an external display and I’m wondering if there is any way to try to debug it. It’s a portable, battery-driven display branded “Uperfect USteam G16”. On a computer that it actually works with, it shows up in niri as:
Output “PNP(YUK) REALTEK demoset-1” (HDMI-A-1)
Current mode: 1920x1080 @ 120.003 Hz (preferred)
Variable refresh rate: not supported
Physical size: 340x190 mm
Logical position: 1536, 0
Logical size: 1920x1080
Scale: 1
Transform: normal
Available modes:
1920x1080@120.003 (current, preferred)
1920x1080@120.000
1920x1080@120.000
1920x1080@119.880
1920x1080@119.880
1920x1080@60.000
1920x1080@60.000
1920x1080@59.940
1280x1024@60.020
1280x720@60.000
1280x720@59.940
1024x768@60.004
800x600@60.317

The display works just fine on both my main stationary computer, my work laptop and an RPi4 i had lying around. And with the RPi4 I’m even using the exact same cable setup (micro-HDMI to HDMI adapter + HDMI to mini-HDMI cable).
And not to be outdone, the Pocket Reform also works just fine with two different tabletop displays and my TV.
But as soon as I connect the portable display and the Pocket Reform, nothing. The display just stays on “No signal” and the Pocket Reform doesn’t seem to recognise the display at all. Both Gnome and niri can’t see the display and nothing shows up in journalctl when I connect/disconnect it. Starting up with the display connected doesn’t change anything.
Does anyone know of a way to debug this or should I just write off this display as “inexplicably incompatible”? It is really annoying because I got the display specifically to use with the Reform, but I can probably still get a return on it.
It almost feels like I should start looking for the prankster demon that’s clearly hiding somewhere in my apartment.

2

Which processor module does your Pocket Reform have?

3

It’s an RK3588 32GB/256GB module!

4

Just a little update on this!

After reading the thread here:

I took a chance on a Club3D CAC-1334 adapter (active HDMI →USB-C). And as I suspected, the active conversion sidesteps the weird incompatibility in the direct hdmi connection, and it looks like it works perfectly from the short test I’ve done! The display is battery-powered and will provide enough power through the USB-C connection for the active adapter.

In short: If anyone has had their eyes on the above-mentioned portable monitor, the hdmi connection doesn’t seem to work with the Pocket Reform (at least with the RK3588 module), but an active converter like the Club3D one may well solve it.

3 Likes
5

Fantastic to hear these result, just ordered Club3D CAC-1333. Thank you for your testing.

6

Hey! I’m sorry if my success may have misled you a bit.

The monitor I’ve tested this cable with is the Uperfect Usteam G16 that I mentioned in the beginning of this thread. It has its own internal battery and charges through a separate USB-C connection.
That being said, it might still work! I couldn’t find the specs for a “Vaio Vision Pro+”, but if it works like this one:

then it looks like it doesn’t have an internal battery, but it has two USB-C ports and you can power the display with a power adapter through one port, and then it passes through power to the other port which would allow you to power and use the Club3D display adapter.

So I hope it works out for you!