On Cheap Hardware and Misbehaving Monitors

tl;dr: Cheap stuff can malfunction in unusual ways

I have a history of buying cheap hardware out of necessity. This has not changed in more than ten years. I wish it was different; but scrimping and saving and buying cheaper, off-brand is the only way I can afford to do things. That said, I am lucky be able to afford what I can afford, it is definitely more than some who are less fortunate.

I have a triple monitor setup, which some might call an unnecessary luxury; but with my eyesight being what it is more real estate means being better able to both fit a reasonable amount of things on the screens at a reasonable visibility.

Each of the three displays is 27″ and capable of a resolution of 2560×1440 at 60Hz. They are all also ‘cheap’ (relatively speaking) Korean knock-off imports- brands such as PCBANK, Crossover and DGM- the last of which I have at least come across before, in the form of the cheap TFT monitors referred to in the post linked at the start. At least they have a track record!

The third thing that these monitors three have in common is a tendency to malfunction; each in different ways. Taking them in the order of purchase, which dates from about five or six years ago to less than six months ago:

  1. PCBANK – The only one I bought new. Makes an audible noise when displaying white or mostly white (eg a a mostly text web page, such as Wikipedia). Also occasionally displays a distorted image for half a second before coming to its senses.
  2. DGM – intermittently blanked itself under Windows
  3. Crossover – If turned off or doing into standby, won’t turn back on for 5-20 minutes. Possibly a backlight issue. As a bonus, it was bought second hand and came with its integrated plastic monitor stand removed; the only way I could see to reattach it would be to separate the plastic casing, which I got halfway to doing before I figured I would purchase the monitor mount[s] I had been intending to for years

In addition, the transformer for the PCBANK or DGM monitor developed a fault which made my speakers screech like a banshee requiring me to take the highly-technical step of moving the transformer further away. Then it started buzzing itself, and needed replaced.

Those transformers are beasts, incidentally- 24V 5A or 120W.

These faults range from irritating to intolerable, but I reckon that if I had three monitors from reputable manufacturers at a commensurate price, I wouldn’t have the same issue with malfunctions.

Intermittent Monitor Blanking

tl;dr: Using a better-rated HDMI switcher improved the situation

For the past… maybe six months to a year one of the monitors I have has been ‘blanking’. That is, it will display properly most of the time, but intermittently go blank for around three seconds before the display reappearing. Strangely, the behaviour only occurred:

  • under Windows, not Linux
  • when using an HDMI switcher

For whatever reason, the issue got much worse in the last couple of weeks, where instead of happening once every five to sixty minutes (or sometimes not at all), it was happening back-to-back, several times per minute with an intolerable frequency. The situation was untenable.

I wondered about interference from other nearby cables, but adjusting them didn’t make any discernable difference. The monitor was running at 59Hz, but stepping it up to 60Hz made no difference either (and Windows 10 set it back to 59Hz). If anything, increasing the frequency may have made the problem worse.

So I figured the issue was the cheap HDMI switcher that I have. I don’t quite recall the circumstances of buying it (never a good sign), but it would have been cheap and therefore unlikely to be rated for 2560x1440x60Hz. After replacing the switcher with one with was rated for ? 2560x1440x60Hz, the issue seems to have mostly resolved- there was *one blank, but I think I can tolerate that.

For anyone else having a similar problem, allquixotic had the following to suggest for potential causes:

Periodic blanking could be: loose cable/connector; bad HDMI port; bad HDMI codec on the GPU/mobo; EMI interference on the cable (e.g., crosstalk by contact with another cable); or, yeah, insufficient cable quality for the data quantity being pushed… also could be pure software

you know, it could simply be Windows driving more data to the monitor; have you verified Windows isn’t overclocking the monitor beyond 60 Hz?

or it might be a GPU issue — Linux tends not to even use the GPU very often unless you’re decoding video, using the animation “whizzy” effects of a compositing window manager, or explicitly an OpenGL application (which in modern times could actually be a typical web browser, but not for everything)

*: I can’t quite explain why the problem only occurred under Windows, but I’ll wave my hands and say “driver differences” while nodding sagely.