Greetings! I'm the proud owner of around 10 Rpi's, ranging from b+ to the latest 4 and it's with the latest one that i'm having headaches. First of all, a congrats is long overdue to the Rpi Foundation (and all the people that worked on every project, SW devs, HW devs, Testers, Forum moderators,...) for their tremendous job in popularizing this great and versatile credit-card-size computer!! And for listening to the community and upgrading the existing 3b+ to the 4b with the things that we ACTUALLY WANTED!! So, to them, i tip my hat.
So, as everybody knows by now, the Pi 4 has 2 HDMI ports (wowowow!) and great possibilities. The thing is - and that i was not aware of, but makes sense - only 1 HDMI has sound, at least in my case. Whenever i connect the micro HDMI cable to HDMI 0, everything works flawlessly, sound, image, resolution, no complaints whatsoever. BUT, HDMI 1 is another story, at least in my case. Image/video wise, i have nothing to say, it performs equal to HDMI 0, but regarding sound...well, it's a work in progress. I absolutely have NO SOUND on HDMI 1. Just using the HDMI 1 port, i get video without issues but no sound. I think i caught a glimpse at another thread on the forum regarding this issue but not many people have come forward to the spotlight to confirm this issue. I already added the hdmi_preferred=1 to the config file but with no avail. I recently added 1.5mm thermal pads to my pi 4 (replacing the 1mm ones that came with armor dual fan case) and i tested the HDMI ports after that. My first thought was "Cr*p, i must've broken some lanes when i screwed the case" but apparently not, the board does seem normal, no bents, no curves, straight as a knife and the screws are definetely NOT overtighten. So, to sum up:
1 - Is this behaviour normal on the pi 4?
2- Is there a workaround to force sound on HDMI 1?
Someone said around "here" that it was a flaw and not correctly tested by the Rpi Foundation, comparing to a car without brakes. I DO NOT AGREE. Every single product has issues when it arrives to the market, even cars get injectors micro code update, ECU corrections and replacement parts / recalls so this is PERFECTLY NORMAL! It just needs some fine tuning, it's not the end of the world. Even the best SW devs in the world can only forsee so much in the near future, that's why updates and upgrades exist! Nonetheless, i still think Pi 4 is definetely a HUGE ACHIEVEMENT! So, Rpi Foundation, my sincere thank you and well done!!
P.S. - If anyone wants to know, Arctic 1.5mm thermal pads (6W/mK) reduced the temps by around 3-4º C compared to the ones shipped with the case. Will try with the Thermal Grizzly Minus Pad 8 1mm (8W/mK).