Sony A8H to A80J mainboard upgrade possible?

[TerraPhantm]

I have a Sony 65A8H. Always bothered me that it doesn't have HDMI 2.1. I noticed the A80J board appears quite similar. And comparing some wiring diagrams in the service manuals (albeit A9G vs A90J since I couldn't find the A8/80 manuals), things appeared quite similar. And my understanding is the panels between the two TVs are more or less the same.

So I decided I'd experiment a little bit.

I bought an A80J board. Left the speaker connection unplugged because it doesn't fit. Changed the power connector to fit the new board. Plugged in everything else.

When I power on, I got flashing white and red LED. Downloaded the latest firmware, plugged in the USB. White LED is now blinking, seems like the board is upgrading its firmware.

Board seems to reboot. No picture. I notice the toslink LED isn't lighting up anymore, but the main power LED does turn on, and it seems to respond to button inputs (white LED blinks when I used the remote). I notice that the USB flash drive now has a bunch of android related folders on it, so it does seem like it's booting. Attempt a forced factory reset, and still no behavior change. And then finally eventually I get an 8x blink red LED (4KBE error?)

I figure maybe there's a TCON compatibility issue, and I buy an A80J tcon, plug that in. And behavior doesn't change. Still no picture and eventual 8x blink red LED.

Plug all my original hardware on it and TV works fine. Just for posterity I did try the A80J tcon with the A8H mainboard. No picture, and 5 blink red LED. Also tried a spare A8H TCON. That one did work (without even requiring a re-pairing procedure), but the picture had a lot of burnin-like artifacts. Service menu now has a panel ID error stored, presumably from when I tried the A80J tcon.

I also dumped the eMMCs from the A8H tcon and A80J tcon (as well as a second A8H tcon). They all seem laid out pretty similarly. Some IDs that are different which I assume are panel IDs +/- serial numbers. And a whole lot of what I assume to be calibration / aging data.

Is this straight up an impossible upgrade, or is there anything else I can be trying?

TCON dumps if anyone is interested https://mega.nz/file/t6c3gT6S#--YAKz...N0jgOLKMF1agDc (the EMMCs are 4GB each, but they compress to around 100MBs +/-; boot0 and boot1 are blank, so you can dump and flash these with a simple USB to SD adapter)

[TerraPhantm]

Re: Sony A8H to A80J mainboard upgrade possible?

Since I can't do much with this mainboard right now, I removed the eMMC and mapped out the vias to the associated pins. In theory should make in system programming possible. Going to see if I can make a valid dump of the new board I have coming in before I start messing with it.

Oh and if anyone has any advice for getting useful data out of the emmc dump, I'd appreciate it. This emmc does appear to use the boot0 partition as well as the rpmb, so you'll need a PCIe mounted SD reader or something like an rt809h to get a complete dump

[TerraPhantm]

Re: Sony A8H to A80J mainboard upgrade possible?

Okay, got a second board with attempting to pair to an A80J tcon instead of the A8H tcon... and exact same sequence of events. I did manage to mount the partitions in the emmc dump noted above, but unfortunately the interesting stuff is encrypted, and the keys appear to be securely stored on the microcontroller itself. So can't really analyze anything there. I give up at this point.

At least I gained some bga skills out of this adventure. I'll eventually just get myself the 77" A95L and move this tv to the bedroom

[Bruce_9119]

HI. I live in Taipei. My English is not good. The following is translated by GOOGLE. I want to share my experience of changing the motherboard. SONY OLED models after android_APK-TV.A8G, such as google_ZIP-TV..A8H.A9G.A9F.A80J.K.A90J, etc. Whenever you change the main board, the main board will lock main board and 8 times blinks when using different models (I tried to decode EMMC with RT809H programmer). So don't try to do this again. I emphasize that the only main board that can use A8G is of course you have to change the main board power supply or directly use the full set of A8G main board + power board + sensor board to light up the A8H.A9G.A80...etc screens to let you know that the screen is faulty. Even if the screen cannot be lit, it will not lock or flash 8 times. Although the screen can be turned on, some colors are incorrect. Annoying SONY. In order to prevent us from repairing the TV by ourselves, the traps set by SONY are getting more and more.