Onkyo RX-NR809 hdmi input 1 -5 not working.

I have seen this before and you are likely correct. Those SII chips do break down from time to time. IIRC there was a way to test for this and it required measuring the resistance of the primary voltage rail. When it drops too low, the chip is essentially dead. Afraid I don't recall the values I used to see but Tibimakai may recall.

These chips aren't too hard to replace but you do have to be careful because the center of the chip has a big ground lug on the bottom so much like the DSP, you have to mask off the area and hit it with a pile of heat until that solder under the pad releases. The second challenge is that when you pull this chip you will leave some solder on the chip and will need to add a small amount back to the pad so that the lug re-attaches. The way I do this is to add a touch of solder and then place the chip roughly in place. What I am looking for here is that if I hold one side down, I expect to see a 0.5-1mm gap on the other side. Once I have this gap, I lift the chip and apply some flux to the ground lug. Next, I carefully place the chip and solder 5 or 6 pins on each side of the "down" side of the chip (the other side will still be lifted by 0.5-1mm). Next, I reapply the heat wand to the chip and heat it until the "up" side settles down onto the pins. What this confirms is that the solder under the chip has melted and bonded to the ground lug. Once I achieve this step, I solder the rest of the pins down.

HTH
Todd

if you have trouble sourcing one let me know. I might have a couple lying around and since I don't fix Receivers much anymore, I could let them go.

Good point on traces. One trick I have used is to spread solder across all of the pins to tie them all together. In this way I can use a small pin to "poke" each side to make sure that the solder is all molten before I try to lift the chip off. The hassle with these ground lugs is that they can form a small vacuum that tends to make the chip feel like it is still tied down when in fact the solder is all molten so after checking that all of the solder bridges I made are truly molten I often resort to using the vacuum attachment and forcing a small "tug" to get the chip to release.

If you try this without creating the solder bridges first, there is a higher possibility that one or more of the traces will still be affixed causing a tear (as Tibimakai suggests).

I don't recall if it was the RZ800... Sorry

IIRC if the impedance between the voltage rail and ground was approaching 50ohms, the chip was bad. A good chip measured closer to 80 ohms

GREAT JOB!!

yup. I always install at least 2 screws in HDMI ports (MAIN OUT and HDMI1) just to make sure I have a solid ground plane before powering on a system.