Help required for de-bricking omega2+ from hard brick
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Hello, while I fiddling with Omega2+ bootloader, I accidentally erased bootloader. Of course, it became hard brick as result.
However, I managed to de-solder it's EMI shield can and attached SOIC8 clip on flash chip and tried in-circuit programming.
While vanilla flashrom doesn't know how to handle 25L25645GM2I-10G, I applied following patches to make it work with it
https://patchwork.coreboot.org/patch/4459/
https://patchwork.coreboot.org/patch/4461/
https://patchwork.coreboot.org/patch/4463/
https://patchwork.coreboot.org/patch/4460/
https://patchwork.coreboot.org/patch/4464/
https://patchwork.coreboot.org/patch/4462/
https://patchwork.coreboot.org/patch/4489/
https://patchwork.coreboot.org/patch/4490/
https://patchwork.coreboot.org/patch/4491/
https://patchwork.coreboot.org/patch/4492/Flashrom recognized flash chip and able to dump and flash chip. I dumped flash and applied my previous mtd0 dump from fresh Omega2+ on extracted image and re-flashed it. Although it seems doing some initializing steps, it does not boot correctly. It prints Onion Omega ascii art and code pointer relocation message but it doesn't do anything after that.
Does anyone can provide information about what is missing now?
Thanks.
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@perillamint-. You sure you didn't mess up the WiFi firmware-partition? I hope you did take backups of more than just mtd0.
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@WereCatf I took backup all of mtd blocks. Of course, I also backed up mtd3 -- factory calibration partition.
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@perillamint-. Did you happen to notice that it says your Omega2+ now has only 64KB RAM? I just noticed that. Looks to me like your RAM has come loose and isn't making proper contact with the PCB anymore.
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@WereCatf Uh-oh... I didn't noticed that..
So it means, while I de-solder EMI shield, my iron (approx, 350 degC) damaged BGA balls and broke some contacts and I need heatgun to rework RAM.
Thanks.
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Could be either the RAM, the MT7688 processor, or something in between.
This has been seen by others with new-in-box Omega2, and I had it happen with a different brand of MT7688 module, but was able to fix it by reheating both chips.
Of course if you loaded a custom U-Boot it could also not be correctly using the flash, but it looks like you simply re-loaded a backup of the official one. Not clear that there is any difference between 2 vs. 2+ in the build, but if so did you match that?
It's worth seeing if finger pressure at power-on gets you a different result, before you start reheating.
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@Chris-Stratton I'm planning to buy cheap rework station like this https://www.adafruit.com/products/1869 and try reflow both chips.
I'll report back with result. (maybe 2-3 weeks later?)
Thanks for sharing experience with other MT7688 boards.
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IMHO the hot air stations with the fan in the handle are preferable - I was skeptical at first, but not having that thick heatproof hose makes them a lot more convenient. I just wish they'd make the handpiece unplug from the base.
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I reflowed omega2 but it didn't fixed it.. It still saying it only has 64k RAM..
I think I damaged PCB while removing EMI shield..
Well, thanks everybody.
