Мои познания в ремонте данного вида техники: Любитель (делаю только для себя) Наличие схемы: Service manual, remont-aud.net file sharing Hi everyone,
first of all, my apologies - I am neither good at Russian, nor do I know the Russian version of Cyrillic, so I'm using English, hoping it's going to be okay with you. I do have my good friend Google Translate for exploring this forum otherwise. I have something I consider a good success and I wish to share it with you, but first I want to confirm that it is okay to do so on this portal.
I've been using my Yamaha RX-V475 as a main home theater receiver for a couple of years now, connected to my TV via ARC, with pass-through sound output. The receiver itself is great, it does everything I want for the most part, but it has one very annoying issue. Codec transition from anything into E-AC-3 (DD+) is just broken over ARC. Every time I load a DD+ content from the streaming services or any source whatsoever, the sync lock just drops and codec negotiation fails. The cause is a baked-in misconfiguration in the DSP firmware. On this input the DSP is set to skip bitstream detection whenever the incoming carrier is above 48 kHz, and DD+ is the only format that arrives above it, at 192 kHz. So the receiver never looks for the DD+ burst and instead reports the stream as 192 kHz PCM. So, every time I load DD+ content (or if a new episode of a show auto-plays), I have to switch the inputs to trigger a full re-acquisition and make DD+ bitstream sync and play.
Since this hardware is now more than 13 years old, and is no longer actively supported by the manufacturer, with the last firmware release being almost 9 years old - I took it for granted that I don't want to throw it away because of this annoying problem (as it is still a perfectly good hardware), and I decided to attempt to patch up the firmware and make DD+ work as intended. After several days of some good reverse engineering, I am happy to say that I have a RX-V475 1.34 firmware image with patched DD+.
The modification is minimal, just a flag in the DSP's setup for that input, the high-samplerate scan enable, which Yamaha already sets on the HDMI inputs but left off on this one. The firmware has been carefully modified, flashed onto my real device and tested thoroughly. Switching between other codecs and DD+ now works as intended. Flashing can be done via ordinary USB update from the advanced setup menu, as the firmware checksums are recomputed and the final binary is properly packaged.
I consider my ownership of this device I paid for to give me right to fix what I see is wrong with it after the manufacturer decided to deprecate it. That said, I understand there might be rules that prohibit the distribution of this firmware here. If the audience here (and moderators) are still interested in having this version up for annoyed owners to have a choice - let me know in the replies and I will either upload it in this thread as an attachment, provide it via my cloud drive as a link, or upload it in the firmwares or file sharing section.
I cannot guarantee the complete safety or take any responsibility for your devices, I am just an enthusiast with some programming, reversing and broadcasting experience who likes to fix his things (my way).
Файлы
Прошивки
Продажа
Литература
Статьи
Зарегистрировано всего