Synology MR2200ac mesh router, UART connection - login details?

[spleenharvester]

This particular unit powers up, LEDs behave normally, but broadcasts no SSID, will not mesh with any other routers. Plugging in an ethernet cable from a Windows laptop results in "unidentified network" with an autoconfigured IP address and no response to pinging 192.168.1.1.

I was able to log into serial/UART by connecting the 6-pin header to the GPIO on a Raspberry Pi Zero W (GND to GND, TxD to RxD, RxD to TxD, no connection between +3.3V as it is supplied on both sides) using Minicom, command:

sudo minicom --baudrate 115200 --device /dev/ttyS0

Upon powering the device it looks normal to begin with. But it looks like it is mid-upgrade:

Found an upgrade file on data volume. Begin upgrade
create upgrading flag to keep upgrading status.

But then fails:

End upgrade procedure
============upgrade
Exit on error [7] Version number not match...

Then proceeds to whine about how it can't find wlan0, wlan1 or eth2, and lists off the only installed devices - these being eth0, eth1, gbr0, lbr0 and lo.

I am guessing I just need to clear the upgrade flag and/or reinstall it from UART by providing the SRM and BIOS files on a USB stick. The problem is it then leads me to a prompt with

SynologyRouter login:

And then prompts for a password after this is typed in. I cannot for the gd life of me figure out what this is. The router has been reset at the back. I've tried:

admin / password
admin / synology
admin / <blank>

And various other permutations, I cannot find anything that works. SRM definitely has a default account called "admin" as I can see it on my RT2600ac but cannot see what the password might be.

Any idea what it might be or whether I can somehow bypass it to do the upgrade?

[spleenharvester]

Okay so user is root, password is 101-0101 (apparently this is derived from the date and changes every day? - but since mine has no date set that is probably why this works). Will update if I can fix.

[spleenharvester]

Info for anyone stumbling upon this in the future with a similar problem - I didn't have any luck with this unfortunately. I couldn't entirely figure out what was wrong other than an upgrade seemed to have failed, possibly related to a VERSION file being corrupted somewhere. I tried mounting /dev/sda5 and /dev/sda6 and clearing all the upgrade files + flags but something kept putting them back. I think possibly if you get an update .pat file onto the device you might be able to install it using the installer at /usr/syno/synoupgrade. I was unable to do so via ethernet as the device could ping the default gateway but would not connect any further. The device does not accept FAT32 or exFAT drives in this state, only ext2/3/4, so if you format a drive that way and load a .pat file onto it you may be able to mount it by plugging the drive into the USB3 port at the rear. The problem is further confounded by the fact that many default programs are missing (sudo, nano, apt and so on)

synoupgrade also has some other functions incl recovery, not clear how they work but in my case they always failed

Unfortunately between reboots I somehow fudged my device to the point that it would no longer even load the kernel so I abandoned any further efforts.

[CapLeaker]

I tried mounting /dev/sda5 and /dev/sda6 and clearing all the upgrade files + flags but something kept putting them back.

Manufacturers cracked down on a vulnerability years ago. When you do a reboot, it will reverse all changes you had made to the boot process. Same thing happened to me on a different device. In one way it is good, but looking at a repair perspective, its a real pain in the @$$.

[stj]

find the backup it restores from and edit that too

[CapLeaker]

stj
I tried that a few years back on a NAS in order to make a backup from one NAS to a different one. Worked fine for years until a certain update. I had modded the boot a little to basically auto start a certain service. Well, after that update it would default the boot. So on each start of the NAS I would have to ssh in, start the service and get back out manually. Then do the backup. Needless to say, I didn't do that for a very long time.
Not sure how to get around it and never solved that issue, since I found a better way of doing things. Since then the old NAS is just sitting there doing nothing.