When looking at the Ethernet ports, the right hand side. It was hot enough that I had to let it go. it was as hot or hotter then a cup of coffee. The Temp on the system/health after letting it sit for a bit was 55Deg, this was after I let it cool for a bit when I powered it off.
Its been on for hours now and the temp is 32 Deg so its normal.
Just looking through the vent holes, I would say the hottest part of the case was on the right side when looking at the Ethernet ports. Inside there is a heatsink cose to the LCD screen, I'm guessing this is the CPU? To put it in perspective better, the HOTTEST part was the right side of the case, but the other side (Left) was also hot but I could hold it from that side.
I do recall that I tested a speedtest from this device to another MikroTik CRS 24 port just to see the max speeds I could get over the Ethernet. The speedtest said at one point " Could not continue, no such test"
This test was from a CRS125-24G-1S-2HnD. The test stopped on the RB2011, and the data rate showed a few K of data, where as on the CRS it showedsome number, 400+ Mbit or something. I then relized that the RB2011 was assigning IP's so I had to unplug the network cable from the CRS, but I left the RB2011 powered on, just sitting on the desk. I left it probably for 30-45 minutes when I started to smell the "fried electronics" smell, that's hen I picked it up and I actually dropped it because it was that hot, and said a few profanities.... something like " holy F___ that's hot" I relized pretty quick that this wasn't normal, that's why I unplugged it.
Just thinking about it now, I cannot recall if I had the Ethernet cable unplugged for that 45 minutes or if it was plugged in, on ether 2 on the RB2011. I checked the graph for the port that it was connected to on my CRS125-24G-1S-2HnD and that port only has a very short duration on the graph no higher then 50 Mbit, not any where near 30 - 40 minutes, so I can rule out that the speedtest was running that whole time, even if it was, the temp should not of got that hot.
I also just remembered that I seen that port 10 had POE out, so I plugged in a UBNT Rocket M5 with a short 3 foot cable, and had it plugged in for a couple minutes, and just looked at the POE stuff on that interface, it said powered on, and didn't show any current draw level in winbox for the port 10 POE. I did a power cycle from within winbox for 5 seconds which is the default. But the RM5 wasn't hooked up longer then 2 minutes.
Seems ok now, not hot, just a warm 32 Deg
** EDIT, While posting the above, I did the exact same things as when I first did them, other then the upgrade from 6.5 to 6.23, and the board temp has maintained the 32 or 33 deg. Well for at least 10 minutes while typing the above.
I should also point out, this RB2011 is NEW, I just got it and upgraded from 6.5 to 6.23 right away, so I do not know if the overheat would of happened on ver 6.5....