Hi, I recently purchased the Waveshare 7 inch 1024x600 HDMI display to install on a Voron 2.4 and driven by a Raspberry Pi 3. I have only just completed the printer, so am testing it out for the first time. Initially I set the screen up according to the information on the Waveshare site, using the standard config.txt settings. This resulted in severe interlace-like flickering, and graphical corruption on the display. Changing hdmi_drive to 2 eliminates the flickering, but on either setting the screen has a shadow of what’s on the current display a few mm lower than the existing image. If I navigate to another page the shadow of the previous image remains, and will continue to appear even after powering off/on the device, and before the interface has loaded. Even stranger, if I unplug the HDMI connector the shadow image becomes brighter and looks like a normal image. Since this happens even when powering on the screen with no video input, it’s clear that the shadow image is stored in the screen itself, but does not appear to be image retention as such – almost like the video buffer isn’t being cleared. There is also a persistent bright purple line down the leftmost edge of the display.
I initally assumed this was something to do with the settings on the Pi, but after further experimentation I believe the screen is faulty. I tried hooking the screen up to a Windows PC, and while the PC (which is not supposed to require any specific configuration), and while the PC desktop displayed, a shadow of the last KlipperScreen image that was displayed before unplugging from the printer was still coming up. After moving the screen back to the printer, it now powers up bright white instead of black, with all colours inverted and the corners faded out (see pictures). Last night after keeping it on for 15 mins or so it reverted back to a black screen with correct colours, but turning it on again today it has gone back to bright white.
Other things I have tried:
- Different HDMI Cable
- Different USB cable
- Hooking the USB cable to a higher capacity power supply
Some pictures below, although based on this I am now pretty convinced this is a faulty display and will need to be returned. Any advice appreciated. Thanks.
Image when hooked up to Windows (shadow of Klipper console visible):
Image of inverted screen. Note no display on corners:
Booting up today:
And Klipperscreen desktop today (again showing white instead of black background, and colours inverted. Center of screen faded out: