Samsung monitor strange behavior? Answered
I have a samsung S27A350H 27" 1080p TN Monitor which for a long time has worked just fine, permanently plugged into the HDMI of my old desktop. However I now have a better laptop which replaced the desktop, but I find that the monitor occasionally will not display a picture when plugged into my computer. I have nvidia display output settings set to output 1920*1080, 60p, with full (not limited) 8 bit colorspace. I do not know the settings of the HDMI output.
I find that if I close my laptop lid, W10 goes into either a sleep or hibernate mode, and stops providing a signal to the monitor. If I wake windows again, the monitor will not display anything. Windows appears to detect the monitor fine and extend my desktop as it should when this monitor is detected. However the monitor appears to bounce between looking for a "digital" and "analog" source (HDMI and VGA respectively)
Unplugging and replugging the HDMI connector has no effect. Windows detects the monitor fine, monitor does not. Changing the output resolution, frame rate, and colorspace does not appear to change this behavior. The monitor requires a deep power-cycle. Powering it off for several minutes (supposedly to allow charge to bleed away from internal capacitors.) usually (but not always) temporarily fixes the issue. The length of time needing to be unplugged seems to vary between seconds and days.
When the monitor enters this nonfunctional state, no HDMI signal is detected. (tested by replacing my computer HDMI source with a raspberry pi. I did not go so far as to adjust the HDMI output settings of the Pi by editing the config file, but the settings were previously changed to optimize the picture quality with this particular monitor in the past anyway.
This monitor appears to have a simalar issue with the VGA adaptor. However fixing it is generally a matter of unplugging the VGA and plugging it back in again, or opening up the display settings on W10.
Online sources appear to suggest that a firmware bug in the monitor is the culprit, and the only way to fix the monitor is to connect the monitor via VGA and use the samsung firmware tool for this monitor to update / reflash the firmware,the explanation being that a bug in the firmware causes it to overwrite parts of itself, corrupting itself as a result. However the executable provided by Samsung immediately crashes after a successful installation of it and the driver when clicking to reflash the firmware in the software. I found no information regarding the error message that appears. (note my current and only laptop does not have a VGA output. Not sure if this is the reason it crashes, the error message does not give much detail.
When I first received this (supposedly broken) monitor from my uncle for free, I found that it was under the warranty period and the problem at the time was that it would not display VGA or HDMI signals. Samsung offered to repair the monitor under it's warranty, and since, it has worked fine, being connected to my main computer permanently. I suspect the problem then is the same one manifesting now.