Sony receiver STR-DN1080 - CLEARING loop - corrupt firmware

[FlyingHippo]

Hi there. Yesterday i bought a secondhand Sony Receiver STR-DN1080.
It worked fine, but i wanted to get rid of all the previous owners settings, and start from scratch.

So i followed the instructions provided by Sony
https://helpguide.sony.net/ha/strdn108/v1/en/contents/TP0001221267.html

Now the receiver just keeps flashing "CLEARING", and after 5 minutes it restarts and repeats.

None of the buttons react to presses. And as soon as it is plugged in it goes into the "CLEARING"-loop.

As it is out of warranty SONY is of no help.

A repair center would charge a fortune to replace the mainboard.

I did manage to find the service manual for the receiver (https://elektrotanya.com/sony_str-dn1080,str-za810es.pdf/download.html#dl)

(Attached picture)
On page 49 it shows the pins
RX+
RX-
TX+
TX-

So i was thinking if i could flash a new firmware manually using something like an Arduino?
I managed to do this a couple of years ago with a HP All-In-One computer, which had i corrupted BIOS

Does anyone have an idea of how i could go about doing this?

[FlyingHippo]

ARgh. Just spotted that the pins i mentioned are for the LAN connection

[squadchannel]

Yes, TXD and RXD would be irrelevant.
I would guess from that diagram that the firmware is written to NANDFLASH.

If there is some kind of external software to update the firmware, it may be possible to recover it.
It is very likely that the file in that updater is probably a binary inside FLASH.

But that FLASH is probably SMD. Do you have the hardware to desolder it and read/write it, e.g. TL866?

If you do not have that experience, it will be very difficult to repair.

ps.
It was sold until recently and still seems to be repairable. (in Japan).
Have you tried asking a repair service?

[FlyingHippo]

The firmware is available on Sonys website
https://www.sony.co.uk/electronics/support/audio-components-receivers-amplifiers/str-dn1080/software/00275368

the zip-file contains to bin files.

Sadly i have never worked with SMDs

I was hoping to just attach some leads directly to the right chip and flash it that way.

I have nothing to loose. The receiver is a paperweight right now

[FlyingHippo]

So. I just tried taking the lid off and poke around a little.

At first glance, no blown caps.

I then tried disconnecting ribbon cables one at the time. With no difference.

But there were two ribbon cables connecting the HDMI board to the AMP board. If i disconnected either of those, the "CLEARING" text only blinked 4 times, then there was a pause and it started over, the power supply didnt click though.

Coming from a software development background, my thinking is that the reset procedure crashes, because it cannot contact the AMP board. And then starts over.

Whereas if i leave everything connected it keeps blinking steadily for about 5 minutes, before i can hear the power supply clicking, and the loop restarts.

So whatever is going wrong when all the ribbon-cables are connected, doesn't cause the procedure to crash. It just eventually times out.

I dont know if the above is of help to anyone, it just thought i would write down my findings.