This story involves:
- 3 monitors with HDMI ports (1 is actually a TV, none are connected to any network)
- 5 computers with HDMI ports (1 with Linux, the others with Windows 10)
- 4 HDMI cables
All of which are in a visibly-perfect shape.
The story started with 1 monitor failing to receive video signal from 1 computer. You know the drill, time to isolate the problem by trying different combinations of (monitor, computer, cable), swapping out 1 element at a time. Boooring...
First surprise: there was no clear, isolated culprit, as each monitor/computer/cable was involved in at least 1 working combination. Let's try again some of the combinations, to clear out potential false negatives, surely I've made a mistake somewhere.
Second surprise: some combinations that worked during 1st attempt, don't work anymore during 2nd attempt. Wow, looking for false negatives, finding false positives. Can HDMI failure really propagate from device to device ?!
Turns out it did. I stubbornly retried combinations, refusing to acknowledge the possibility of an issue that propagates. Soon enough, no combinations worked anymore. At this point, just a couple of hours have passed since this story began... that escalated quickly !
Some of the devices have another video connector available (VGA or DisplayPort), which still works perfectly. But for all of them, HDMI invariably fails to work: devices don't even acknowledge the presence of a plugged-in HDMI cable with a device at the other end.
The only theories I can imagine to explain this propagation behavior are:
- a faulty device overloads HDMI cables, which melt down (internally, without externally-visible trace ?) and stop working
- a faulty device overloads the HDMI controller at the other end of the HDMI cable, burns some of its components, which effectively breaks it
They both seem far-fetched and, as a good citizen, I can't fathom the idea that an actual software virus went through HDMI cables. I am apalled at what just happened, have no idea how to progress and am afraid of borrowing a friend's monitor/cable/computer to make further experiments, lest I would break their precious equipment.
Do you have any idea what could explain this, and how to fix it ?