Yamaha RX-A3050 Working, No Sound

[paulstevens]

Thanks to Iotas posting the A3050 service manual in response to my request in my first forum post, I am starting this thread about my RX-A3050.

Using the self diagnostic mode, function C1-7 reports an error with DSP2, IC920.

Is this part still available? Are there recommended suppliers?

I presume I will have to attempt to remove and replace this part.

Further snooping through the service menu...T4-11 cannot read the FW version of DSP2 (makes sense if this part is defective or the datapath to it is corrupted)

A strange observation: many of the front panel buttons seem to be "off by one", shifted-left by one, meaning that if I press Scene4 button, it acts as if Scene3 was pressed. If I press the "AM" button, it acts as if "Tune <<" was pressed. Is that indicative of something else to check?

If I press the appropriate button enough times it responds correctly, but the "default" behavior is one of being shifted to the right by one.

According to the T1 info, this unit has been running for 341 days, 15 hours, 29 minutes prior to this happening.

Thanks all...This looks a bit daunting but exciting. This unit is pretty well packed inside.

[paulstevens]

Re: Yamaha RX-A3050 Working, No Sound

Service Manual show IC920 as D80YK113DPTP5. That is also the p/n loaded on the board.

The schematic page for IC920 shows "No Replacement Part Available"

searching online for various overseas parts suppliers suggest the part might be available.

Has anyone any experience ordering D80YK113DPTP5 and replacing it on the board? Any advice or suggestions are appreciated.

Thank you

[budwich]

Re: Yamaha RX-A3050 Working, No Sound

what is the history of your receiver... how did it come to this condition?

[paulstevens]

Re: Yamaha RX-A3050 Working, No Sound

Hello budwich, history is unknown. I bought it knowing it had the "no sound but pure direct sound" issue but with the goal of repairing it and setting it up at home.

Tomorrow I will take the Digital1 board into work where I have a good set of rework tools and magnifying scope and look at the DSP pin solder joints and maybe reflow the pins.

Thank you

[budwich]

Re: Yamaha RX-A3050 Working, No Sound

OK... that's tough. Check what the receiver model is in the service menu to confirm that it matches to your unit. Perhaps someone has played with it. There is also a SN captured there in that should be checked. Maybe a board was been replaced and those have not been updated.

[budwich]

Re: Yamaha RX-A3050 Working, No Sound

Have you tried to do a firmware update? Not sure if one can be forced on a unit that is "presenting" the current firmware... but perhaps there was some corruption along the way and a "re-install" might help.

IF it can be done, try doing it via usb as opposed to network mode (ie. wifi or ethernet).

[paulstevens]

Re: Yamaha RX-A3050 Working, No Sound

I checked the receiver model in the service menu - it displays A3050 and "location" is "U" for US model along with number 27, not sure what that means.

I did not see a way to dump the serial number from the service menu - I can only assume it matches. Unit does not look like it was ever disassembled. All the zip ties, tapes, etc, looked original with no signs of overlap, scratches, etc.

Serial number is Y016555SU. Thanks

[paulstevens]

Re: Yamaha RX-A3050 Working, No Sound

As for firmware update, where can I download the image fromso I an transfer it onto a USB stick?

At the moment I have the Digital1 PCB removed for inspection tomorrow. I can try forcing the firmware when I reassemble tomorrow or the day after.

[budwich]

Re: Yamaha RX-A3050 Working, No Sound

I think that the firmware is on the yamaha site.

[paulstevens]

Re: Yamaha RX-A3050 Working, No Sound

I found the FW on the website, thank you.
Visual inspection of IC920 looked good, solder joints looked good. Need to reinstall the Digital1 pcb to check FW version and do FW update if needed. Hope to do that in the next day or two.

I did notice that one of the two big caps in the AMP POWER board (C1822 or C1823) is much looser than the other. I think I should remove other boards to gain access to this board and check/reflow the solder joints to those caps. One is just too loose, and i get the sense I could remove it vertically from the pcb if I work at it enough.

I am soliciting quotes for the DSP chip - have a few responses, one of which is reasonable, awaiting shipping quote. I will check power/clock/reset of DSP2 before I replace the chip (assuming FW update does not resolve the problem.)

[paulstevens]

Re: Yamaha RX-A3050 Working, No Sound

Firmware update completed, but still no sound unless in Pure Direct.

I found some Chinese suppliers who purport to have the DSP, and I am waiting for them to return from the Lunar New Year celebrations to see about getting one.

The built-in diagnostics also report an error with IC64 HDMI Equalizer, but that appears only associated with the front panel HDMI port, is on Digital PCB 2, so for now I am inclined not to worry about that one and still keep the focus on DSP2 for the sound problem.

[paulstevens]

Re: Yamaha RX-A3050 Working, No Sound

I should add that even though the FW update completed (got update successful on the display), it still does not display a FW version on the display or on a monitor hooked up to the HDMI output. It displays only dashes "---" for Sys Ver and Fac Ver

for everything else it displays something other than dashes (except for DSP2 which shows dashes as well, D2-V=-------. It does give a checksum for D2 but I suspect it is bogus, 0x4492DB86)

[budwich]

Re: Yamaha RX-A3050 Working, No Sound

:-( was that updated thru the network or via usb? Doesn't look good based on your current observations.

[paulstevens]

Re: Yamaha RX-A3050 Working, No Sound

Updated via USB.

Following something on YouTube posted by a technician in California, I pointed a heat gun on IC920 being careful not to get anything too hot. It did not take much but eventually I got sound from the unit in regular mode, not just in pure direct. Powering off then on again, it powered on silent, but pressing Pure Direct gave sound, then pressing Pure Direct again resulted in Sound as well, but the only way it gave sound was by entering then leaving Pure Direct mode.

While it was "working" I could see the FW version and FAC versions at 2.86 both on the unit display and attached HDMI monitor. I could also see the version of DSP FW for IC920, and the IC920 self diagnostic also shown as good. Interestingly, the DSP2 checksum was again 0x4492DB86, same as it was before trying the heat gun. The difference is after the part was heated, it would report a valid D2-V. but when could it would be only dashes.

So this pretty much points to IC920 being the failure. I just hope I can get a chip at a reasonable price and try replacing it.

[budwich]

Re: Yamaha RX-A3050 Working, No Sound

great work.... can you post a picture of the area associated with the chip in question? Before you cast "doubts" on its health, you might consider reflowing the pins as there just might be a "poor" solder joint that was help by thermal expansion from the heating.