CRS317 NAND Replacement

Hardware MikroTik hardware general
1

Hello,

Would anyone know where on the board the NAND chip is for the CRS317 and what make/model/type it is?
I need to look are replacing it due to bad blocks even with a very low total write count. Unfortunately, the device is a number of years old and wouldn’t qualify for a warranty replacement.
I need to reboot the device after a while to be able to take a backup etc.

                   uptime: 2d18h26m58s
                  version: 7.4.1 (stable)
               build-time: Aug/04/2022 11:48:11
         factory-software: 6.40.5
              free-memory: 931.0MiB
             total-memory: 1024.0MiB
                      cpu: ARM
                cpu-count: 2
                 cpu-load: 1%
           free-hdd-space: 1332.0KiB
          total-hdd-space: 16.0MiB
  write-sect-since-reboot: 18627
         write-sect-total: 358185
               bad-blocks: 2.8%
        architecture-name: arm
               board-name: CRS317-1G-16S+
2

I: try netinstall, often solve

3

As a word of caution (agains blindly replacing NAND chip): ROS license is burned into NAND chip and if you replace the chip, you loose ROS license:

https://wiki.mikrotik.com/wiki/Manual:License#Can_I_Format_or_Re-Flash_the_drive?

The license price is not low either, ROS level 6 (icluded with CRS317) MSRP is $250 (you can get it cheaper from some resellers) which might add to the cost of repair.

4

Thanks for the input.

Yup, It’s a pity nand chip of $2 would send this device to ewaste..
I have exported the license from the device, would this not work?

From what I can pick up, the chip is: Winbond 25Q128FVSG 1553

5

MT’s own help page suggests one to contact their support before doing anything potentially destructive to device. So why don’t you send an email to support@mikrotik.com describing what you’re after and see what they’ve got to say? They might help you with license migration if they deem your actions acceptable …

6

II: try netinstall, often solve, and you do not lose licence

7

So many writes… are you logging to NAND?

8

Thanks for the guidance.

I did reach out to Mikrotik and they said in a nutshell, they couldn’t help and I would lose the license if I replaced the NAND. They said I would need to purchase a new one.

The device logs 0 to disk, and only keeps the odd backup we save to it in case of an emergency restore. I suspect this device had a bad NAND from day one, and it’s only something, since I obtained the device, put any time in to investigate. I will give the netinstall a bash as I don’t think I did do it to this switch…

Here is a comparison of 2 switches purchased together. Look at the difference in writes vs %bad blocks.

Switch 1: Bad NAND

                 
                  uptime: 3d3h57s
                  version: 7.4.1 (stable)
               build-time: Aug/04/2022 11:48:11
         factory-software: 6.40.5
              free-memory: 931.7MiB
             total-memory: 1024.0MiB
                      cpu: ARM
                cpu-count: 2
                 cpu-load: 21%
           free-hdd-space: 1256.0KiB
          total-hdd-space: 16.0MiB
  write-sect-since-reboot: 21667
         write-sect-total: 361225
               bad-blocks: 3.2%
        architecture-name: arm
               board-name: CRS317-1G-16S+

Switch 2: OK NAND

                  
                  uptime: 3d3h8m39s
                  version: 7.4.1 (stable)
               build-time: Aug/04/2022 11:48:11
         factory-software: 6.40.5
              free-memory: 932.0MiB
             total-memory: 1024.0MiB
                      cpu: ARM
                cpu-count: 2
                 cpu-load: 4%
           free-hdd-space: 1988.0KiB
          total-hdd-space: 16.0MiB
  write-sect-since-reboot: 22001
         write-sect-total: 1666829
               bad-blocks: 0%
        architecture-name: arm
               board-name: CRS317-1G-16S+
9

Don’t recall what file system MT is using for NAND’s in v6 but it might be worth trying to reformat it using Netinstall and if you are lucky all faulty blocks will be added to the “bad block list” on the drive.

10

Yet another reason 16mb of flash is such a bad design choice

in v7 with the bundled package, there are about 2mb of flash free on the device for wear leveling to work on

most of our switches in v6 had about 8.4mb free due to not having Wireless/Hotspot/etc packages loaded.
but v7 takes that workaround away, so i expect to see a higher churn rate of equipment in the future.

11

True, and the cost of 16MB vs 32MB/64MB is really insignificant. I wonder if they did it to stop people using it for “something” else?

I can pick up a 128MB NAND for $2, if not less.

12

III: try netinstall, often solve, and you do not lose licence, and not all bad blocks are defective sectors…

13

Thanks, I’ll give this a go first…

14

Hi,
as a last measure before you throw out your CRS and after you have tried Netinstall:

  1. There is a way to save & successfully reinstall your license key. This procedure works for some RB models, and it was documented as a way of going back from an OpenWRT install to ROS. It might work for your device as well, but there is of course no guarantee:
    https://openwrt.org/toh/mikrotik/common
  2. There are some companies specialized in replacing chips on devices. They mostly do console or mobile phone repairs, but I would ask one, if they are capable of creating a binary dump from the old chip, then let them write it to the new chip.
  3. there is this utility if you are brave enough to do the dump and reflash by yourself, with the help of an Arduino:
    https://github.com/ricardojlrufino/SerialFlashSPI

W

15

Awesome, yeah the plan was to get an electronics repair company to replace the chip as they have the best tools for the job :slight_smile:.
I have exported and saved the license, so at least that part is done in case the device completely dies.

I have found it a bit of a struggle trying to find the 16MB chip though and Mikrotik won’t say what is it, or where it is located.
*I found it on the board…

Does Mikrotik have a service like Dell where you can look up the serial to confirm warranty status?

16

No, is not and is never MikroTik that provide warranty, is your distributor.

17

Ah, so what if you don’t know who the distributor is? :slight_smile:

18

[sarcasm]
Don’t you remember who you stole it from?
[/sarcasm]

19

Ha Ha, I could try all of them I guess :slight_smile:

20

At this point if you do not remember where you sto… [sorry :wink: ] buy the device, is hard to obtain the warranty :frowning: