Adventures in Fraudulent Cable Design02/20/2022 at 02:53 • 0 comments
For some time I've had a need here and there to go from an HDMI video source to an analog composite screen of one stripe or another. I should have just bought myself an HDMI to Composite video adapter box, but in looking for one on Bezo's Instant Gratification Engine of Horror a neat prospect kept popping up. A direct HDMI to Composite cable.
I KNOW I KNOW I KNOW, but I'm not a complete fool. HDMI is a straight digital connection and analog video is a messy little thing, but dang it modern microprocessing is sometimes amazingly cheap and compact, I didn't need the best conversion ever, and I've seen cables with slightly oversized strain reliefs hiding smartypants active components that Do Magic powered from the voltage source of one end of the cable and HDMI has a 5v source. My curiosity and desire to avoid Another Dongle And Wall Wart got the better of me. In a nearly uncomfortably short time later it arrived. I plugged in the googah to the beepboop and.... nothing. Boo..... tried a few other possible variants, but no joy. The listing said it's a general purpose converter cable for just what I was using it for. Bummer.
I was ready to just toss it aside, take my lumps, and move on until I spoke to a member at my Friendly Local Hackerspace who had a similar story with an HDMI to VGA cable. We both guessed that the cable was likely never meant to do anything but bilk the credulous and too lazy to file returns of their cash without the complication of a functional product, IE: that the cable was made from the word go to be nonfunctional crap.
I began taking the cable apart that evening.
HDMI being all digital, there's narry an audio waveform, let alone an analog TV signal the video hardware designers of the 70s would have felt at home dealing with to be had. But as I stripped back the rubber overmolding no smartypants ICs or miniature video scan converters reared their head.
For all the world it looks like they just took an HDMI plug, picked some random pins to solder to random clock and voltage pins just to make it easier to stick the assembly into the strain relief injection die machine.
Above I've highlighted which pins were soldered to the RCA cables, though I don't suspect there was any rhyme or reason aside from "doesn't blow up the first TV we plugged it into this way". With that mystery out of the way, I applied for a refund with Amazamalamadingdong, tossed a quick review into the ocean of happy reviews from what I suspect are astroturfed pay-for-review "customers", and here we are. Watch out for those too good to be true HDMI to [YOUR CONNECTOR HERE] kids. If it costs less than the real converter box it's probably a turd, and most folks aren't gonna bother schlepping a trash cable to Whole Foods and filing a return claim for the cheap cable. I hope whatever dickhead in is minting this trash gets his wechat account frozen.