Originally Posted by oneiro
Thanks for your insight Todd. It looks like repair companies here in Aus are being quoted ~$400 for a replacement HDMI board + labor which is a bit much lol
For a permanent fix, you mention models such as the NR626 will have the latest version of the DTS chip. Is there a list somewhere I can see other suitable models with a donor chip to aid in my ebay scouring?
In the meantime, is there anything I can do for a 'medium term' fix? Can I just keep reflowing the chip with a heat gun every time it plays up, indefinitely?
You can try reheating but once the buffers are worn out the chip simply won't work anymore regardless of what you do. The good news is that TI designed the "D Rev" as a perfect replacement so there are no changes required to firmware nor circuitry.
I don't know of a definitive list but from experience I can confirm that the following boards make a good source for 400Mhz "D Rev" parts (these end in "4" as in D830K013DZKB4):
first generation with "D Rev": Onkyo NR: 525/626/727/828 /RZ800/RZ900 Integra: anything that ends in x0.5 (example: DTR-80.5)
third generation with "D Rev": Onkyo NR: 545/646/747/848 /RZ810/RZ910
Everything after this (ex: NR676) uses a completely different chip.
the second generation with the "D Rev" uses a 500Mhz part (denoted as a '5' at the end ex. D830K013DZKB5). I have installed these in systems that require a 400Mhz part and they seem to work properly. These parts use a 24Mhz clock rather than the 20Mhz clock that ships for the 400Mhz parts so when you install it in a 400Mhz system (with the 20Mhz clock) it seems to step down in frequency and work properly. These models include:
Onkyo NR: 535/636/737/838 Integra: anything that ends in x0.6 (example: DTR70.6)
For the sake of others who may review this thread, when I state that the 400Mhz "D Rev" is a 100% compatible replacement for the "B Rev" parts it is important to note that it is NOT a perfect replacement for the 300Mhz parts used in earlier models like the NR3007/NR3008/NR708 etc. These systems use a part stamped as D830K011BZKB3 or D830K013BZKB3. Since these parts only run at 300Mhz you cannot install a 400Mhz part and expect it to work. The Onkyo repair on these units does use a 400Mhz "D Rev" chip but to make it work, they change the firmware for both the DSP and the MAIN CPU. Unfortunately, Onkyo does not make this firmware available to anyone except authorized service depots which makes it impractical for anyone to attempt this. Essentially, when the chip fails, the entire unit becomes a paperweight.
One last note: In the USA, when Onkyo repairs a board using the new "D Rev" chip, they place a sticker on the chip that says "New" that is visible in the pictures of the board. I have found a couple of boards on eBay that had this sticker and when I purchased the board, I found good DSP chips on them (but had other problems). I don't know if this is the same in all regions and I should also point out that after this post, a bunch of people might start making stickers so be wary.