Problems with ECC

[adsko]

Hey!

I have AX86U, which wont boot. When I check logs, I can see that almost whole nand has uncorrectable ECC errors. I tried to replace nand with new one, but situation is the same (with original memory dump).

I tried to use https://www.snbforums.com/threads/asus-rt-ax86u-rt-ax88u-2048mb-2gb-ram.79610/

But as a result I've got:
IMG?
FAIL

So it looks like this dump does not work on my router.

On original one I can access CFE, but system won't boot (ECC errors). When I try do upload new one by 192.168.1.1, I got ECC errors and it fails.

Any ideas how can I solve it?

 

[RMerlin]

If it`s an ECC error, then it`s more likely to be with the RAM or the CPU, as I don`t think the NAND has ECC, only CRC.

The public specs aren`t very clear, they only mention ECC for the cache:

BCM49408

This high performance CPU has been designed from the ground up for the next generation of Wave 2 wireless applications.

www.broadcom.com

 

[adsko]

There is NAND MX30LF2G18AC which has ECC:

That's why I think my old one NAND has damaged ECC values and now flashing his dump to new one won't work.

 

[adsko]

If it`s an ECC error, then it`s more likely to be with the RAM or the CPU, as I don`t think the NAND has ECC, only CRC.

The public specs aren`t very clear, they only mention ECC for the cache:

BCM49408

This high performance CPU has been designed from the ground up for the next generation of Wave 2 wireless applications.

www.broadcom.com

Do you know layout of memory of nand memory? As I understand, bootload has been encrypted in newer routers, so flashing different dump wont work. So I need to know where the bootloader is to modify dump file a little bit.

 

[RMerlin]

Do you know layout of memory of nand memory?

I don't know, sorry.