Currently, I use two computers: my company laptop, and my personal desktop PC. (I will write more about this one later, because it’s quite magical.) Thanks to COVID, I still work fom home, and during that, I would like to use my desktop’s display as a secondary for my laptop. Well, you can do this by plugging HDMI back and forth between the two, but that gets old quite quickly, so I decided to buy an HDMI switch. Here is when I found this problem.

If you check such switches, you will find out that a lot of the different types made for average consumers (e.g. not 40-input mosters) does not have external powernal. They can get away with this, because theoretically, HDMI feeds some power - so if the switch has anything connected which satisfies this, everything should be golden. But let’s check my case.

• I have an HDMI coming out from the desktop, everything is OK here.
• I have a display, which only has DVI, so a DVI → HDMI adapter is used here.
• I have Macbook Pro, using Apple’s default USB-C → HDMI + USB 2.0 + USB-C adapter for HDMI.

If you plug those together with the switch, the following will become apparent: the display does not provide power to the switch (could it maybe?). The desktop gives power nicely - if you turn it on! From the Macbook, it doesn’t get any power either, because the Apple adapter does not solve this. (This is a fairly common issue based on what I’ve read, as people with PS4s tend to have similar problems.) In the end, I can only use the switch if I have my desktop running while I use my laptop, oh yeah 😆

The solution to this: a weird-looking cable, which picks power from a USB and feeds it into HDMI. Obviously, you can’t buy this in Hungary, so I had to order from Germany. It wasn’t expensive though - but whether it will work? Now that’s a blogpost for another day… 😆