No, you don't need a serial cable to do Netinstall. Having one just makes it easier to debug things when you run into problems.

RB435G should definitely be mipsbe and not smips. I am wondering if the NAND flash chip on your board is bad? smips and mipsbe might be similar enough to each other that maybe the only way that Netinstall distinguishes between them is if a big-endian MIPS board has a flash chip under 32MiB in size?

When your 435G shows up in Netinstall, what does it say in the "Label" column?

-- Nathan

I suspect that you are going to need to figure out how to get your serial port working, so that you can see what RouterBOOT is printing on the console. It may provide a clue about what the problem is.

-- Nathan

I suspect that you are going to need to figure out how to get your serial port working, so that you can see what RouterBOOT is printing on the console. It may provide a clue about what the problem is.

-- Nathan

RouterBoard 435G

CPU frequency: 680 MHz
  Memory size: 256 MiB
    NAND size: 2048 MiB

Yeah, this is what I suspected. The NAND is defective. It isn't even detecting the right size. It probably failed while the router was still running, but it kept on running because it was already booted. When you told it to reboot after the NAND had failed, it never came back.

Probably the only way to fix the board is to swap new NAND chip in place of the defective one. Working with surface-mount components is difficult and you will probably need a professional to help you do it if it's not a procedure you are familiar with or if you don't have the proper tools, so the board is likely not worth repairing. If it is less than a year old, you could contact the distributor you bought it from and have them swap it for you under warranty.

Sorry for the bad news,

-- Nathan

Yeah, this is what I suspected. The NAND is defective. It isn't even detecting the right size. It probably failed while the router was still running, but it kept on running because it was already booted. When you told it to reboot after the NAND had failed, it never came back.

Probably the only way to fix the board is to swap new NAND chip in place of the defective one. Working with surface-mount components is difficult and you will probably need a professional to help you do it if it's not a procedure you are familiar with or if you don't have the proper tools, so the board is likely not worth repairing. If it is less than a year old, you could contact the distributor you bought it from and have them swap it for you under warranty.

Sorry for the bad news,

-- Nathan

I was wondering, if I swap a new NAND chip in place of the defective one, after I do that, can I use Netinstall to install the RouterOS?
If not, what should I do after I swap that NAND chip. Is that the booter will gone after I replace the NAND chip? if it's gone, is it possible for me to make it installed on the new chip?

RouterBoard 435G

CPU frequency: 680 MHz
Memory size: 256 MiB
NAND size: 2048 MiB[/code]
This is strange, cause I know the RB435G has only 64MB, right?
what else can I try? I want my routerboard works.

Do you have a micro SD card in the board? 2048MB seems suspiciously like a card may be present.

I was wondering, if I swap a new NAND chip in place of the defective one, after I do that, can I use Netinstall to install the RouterOS?
If not, what should I do after I swap that NAND chip. Is that the booter will gone after I replace the NAND chip? if it's gone, is it possible for me to make it installed on the new chip?

`
Sorry, I saw this and then forgot to respond to it. My understanding is that RouterBOOT (bootloader) actually lives on a separate (and much smaller) SPI flash chip. I also believe that the RouterOS Software-ID and license key are both also stored on the same flash NOR with RouterBOOT, so you shouldn't lose those either. If you have access to the tools necessary to swap the surface-mount NAND chip as well as the skills to do it, RouterBOOT should still be intact, as should your RouterOS license. In theory, you should be able to just perform Netinstall again and have it work.

If you actually manage to succeed at replacing the NAND and resurrecting your board, I would love to hear about it! It would confirm a lot of my theories and perhaps also give others with failed NANDs hope!

Good luck,

-- Nathan

Did you mean the license will be lost if I replace the NAND chip.

Is it possible to boot from network server, I mean if I have a UBUNTU server in the same network, can I use this bricked RB435G to boot a RouterOS from the server.

Did you mean the license will be lost if I replace the NAND chip.

`
I am sorry if I did not explain this clearly before. If my understanding of where the license is stored is correct, then in theory, you will NOT lose the license by replacing the NAND chip. NAND chip only stores your copy of RouterOS, but the license is located on a separate NOR chip (where RouterBOOT lives). MikroTik has never confirmed this publicly (to my knowledge), though, so I could be wrong. If you decide to try and swap the NAND, it would be a very interesting and educational experiment!
`

Is it possible to boot from network server, I mean if I have a UBUNTU server in the same network, can I use this bricked RB435G to boot a RouterOS from the server.

`
Sorry, unfortunately not. RouterOS assumes local storage is available to hold config, logs, etc. and it would have no idea what to do or where to look for config in a netboot scenario. MikroTik has not engineered RouterOS to support this.

(You could netboot a RouterOS kernel, but that would not do you any good, because the RouterOS kernel's "initramfs" would try to mount local NAND to access the RouterOS userland. The SquashFS filesystem is not part of the kernel/ELF payload.)

-- Nathan

Did you mean the license will be lost if I replace the NAND chip.

`
I am sorry if I did not explain this clearly before. If my understanding of where the license is stored is correct, then in theory, you will NOT lose the license by replacing the NAND chip. NAND chip only stores your copy of RouterOS, but the license is located on a separate NOR chip (where RouterBOOT lives). MikroTik has never confirmed this publicly (to my knowledge), though, so I could be wrong. If you decide to try and swap the NAND, it would be a very interesting and educational experiment!
`

Is it possible to boot from network server, I mean if I have a UBUNTU server in the same network, can I use this bricked RB435G to boot a RouterOS from the server.

`
Sorry, unfortunately not. RouterOS assumes local storage is available to hold config, logs, etc. and it would have no idea what to do or where to look for config in a netboot scenario. MikroTik has not engineered RouterOS to support this.

(You could netboot a RouterOS kernel, but that would not do you any good, because the RouterOS kernel's "initramfs" would try to mount local NAND to access the RouterOS userland. The SquashFS filesystem is not part of the kernel/ELF payload.)

-- Nathan

Hi, Nathan.
I have a master here, he have been doing this job for more than 20 years, and he helped me replaced the nand chip. excellent work.
so I had the SAME samsung NAND chip replaced in the SAME place and i am pretty sure that the new NAND chip is good.
But, when using Netinstall, all things happened just like before i replaced the NAND.
Things displayed in the console, just like before. nothing changed, just like i didn't replace the NAND. it shows 2048Mib.
ALL THINGS Just like I wrote above this post.
So I guess the original NAND was not defective, it was good. there must be something wrong on anywhere else.
oh, you were right about the booter and the key, they are in the SPI flash seperate from the NAND.

Hi, liaobamboo!
Did you solved your problem? I have same issue with Mikrotik CCR1036-12G-4S. After upgrade to latest ROS it does not boot, other symptoms are exactly the same as yours... I also want to replace the NAND chip. Is it worth it?