Originally Posted by Wisiwyg
, anyone else...
Long time lurker... I have followed this thread for a couple of years.. Have an Onkyo TX-NR905 that has been having HDMI issues just like the TX-SR606. About a year ago I replaced all the 15 or so caps originally described as the cause of HDMI going out or unresponsive.
Now, a year later and after the system has been working great, I'm beginning to see HDMI drop outs of a few seconds, sound still on, and then picture comes back. I suspect that the issue is now the other several/numerous caps that @dolivas
referenced in a post a page back.
So I'm considering cracking it open and replacing the rest of the troublesome caps. Does someone have, or can anyone recommend the list of caps to be replaced in addition to the main caps circled in red in several images floating around? Better yet, if you have another image with the other caps indicated, that would be enough.
TIA for any help or suggestions. I'd really like to keep the 905 going for now, at least until the projectors catch up with 4K video and the price comes down.
The problem is, all the electrolytic caps get baked dry by the high temperatures on the board. Eventually, all circuits that have any sensitivity at all to baked capacitors with low storage capacity will eventually begin to malfunction.
The best course of action would be to replace all the aluminum caps on the HDMI but by the time more start failing than the usual suspects, you might also be seeing some issues related to other boards on that hot backplane.
If you insist on punishing yourself, you can check all the IC numbers on as many boards you can get to and change the switching regulator output filter cap(s) for all of them. You can find out which caps are on the regulator with an ohmmeter. You might have to refer to existing documentation on-line if the regulators have Onkyo-specific part numbers.
That still might not fix it though, but it is a start. It might just be that the caps you already replaced failed again. Just be aware that the more often you remove that board, the more chances you have to zap something with ESD or damage a connector or lift a pad.
Be sure you ground yourself at least to the chassis before you touch the insides and also, if you see any place on your HDMI that says 'short to remove' or some such, be sure to solder a jumper across those terminals before removing the board, or you might blow something (the upscaler/on-screen menu seems like it sometimes dies and does not come back with cap change so that might be why, not sure but if it gives you explicit ESD warning probably good idea to comply - I did not know about this on the 606 I repaired and the OSD/upscaler did not recover, but the 706 in process, I shorted before removing the board).
Also be sure to depress the spring clip before removing the ribbon cable, or you will destroy cable and/or connector.
Aside from that, you really need an insider who knows the artwork, or a schematic and oscilloscope, to really identify the actual culprit(s) or at least the most likely suspects. Also, by the time you get through replacing all those caps at retail prices, you might have already invested enough in parts and labor to justify replacing the receiver instead, especially if after all that work it STILL does not function.