I just got Mikrotik CRS326-24s+2q+rm for my home lab, and the first thing I do, of course, is download and deploy the latest available RouterOS. I believe it was 7.12.1
After reboot, none of the connected ports is flashing anymore except for the blue power LED, and I don’t see the router in Winbox / Neighbors to connect to it via the MAC address.
I have tried hard resetting the switch, but it did the same thing.
What do I do now? I’m new to Mikrotik, so any help would be appreciated.
Well something went wrong, that much is pretty obvious. Actually the latest version marked as stale is the 7.18.2.
Your best bet in these situations is to netinstall the device. You’ll have to get both the netinstall program and the routeros software (mipsbe version) from the download page.
Netinstall instructions are here:
https://help.mikrotik.com/docs/spaces/ROS/pages/24805390/Netinstall
and you’ll need to connect to the management port on your device.
Using netinstall can be tricky and/or not work on the first try. There are all sorts of tips & tricks floating around, which may be useful. (Also, there’s a Linux version of netinstall.)
I m currenlty doing the netinstall but its taking forever .. how long does it usually take its been 2 hours already and still says installing/transferring routeros 7.18.2
nope this should be finished under 5 to 10 mins tops, you can try to reboot the device
That you got this far is actually good news. The formatting/transfer only takes at most a few minutes. I only encountered a similar situation when I nudged the rj45 connector loose. (The locking tab, as usual, was broken.)
EDIT: It’s safe to unplug/retry as many times as you have to. There are two pieces of software on the devices, RouterBoot (the bootloader) - this contains everything necessary for netinstall, and RouterOS (the system itself). During netinstall the latter is completely overwritten, but the former is left alone.
I repeated the process and used another NIC that was Intel vs the previous one, RealTek, on my PC, and it worked this time, and was done under 1 min
Glad it worked out. 
Just to get things straight:
__
If original ROS version on device was <= 7.11, then upgrader built in ROS will first upgrade to 7.12(.1) … only upgrader in 7.12 will know how to upgrade beyond 7.12. That’s due to wireless package being split from main package and rename of wifiwave2 package and split into a) main package (capsman), b) wifi-qcom-ac (drivers for AC radios) and c) wifi-qcom (drivers for AX devices).
We had the same issue when we upgraded to 7.12.x. None of our CRS326-24s+ switches booted if they had a UBNT copper SFP module installed. Once you remove the module, the switch would boot immediately. Mikrotik could not replicate the issue, and we had to replace all the SFP modules with non-UBNT’s.
The issue still exists up to at least 7.15.x. We haven’t tested it in later versions.
Thank you for all the help
One correction that I would make is that the CRS326 stopped working after upgrading to 7.18.2, not 7.12.1. I didn’t have access to the CRS326 then to confirm when I was reaching out for help
Also, my CRS326 had two CISCO GLC-T SFPs for RJ45 1GB transceivers plugged in when this happened and when it was fixed using NetInstall