Raspberry Pi 2 not connecting to routers (connecting to switch just fine)

[LegendBR]

I've got a pretty weird problem with my Raspberry Pi 2. If I connect it directly to one of my routers (Mikrotik's RB951Ui-2HnD as main router, Mikrotik's hAP Lite as extender router), it doesn't connect at all, as in there are no LED on/blinking. My other Raspberry Pi 1 connects just fine to either of them, but not the RPi 2. Tried Raspbian and NOOBs, none worked.

As the USB ports seemed to be working fine (used a USB keyboard without a problem), I tried connecting the RPi 2 to a TP-Link switch I have that were not being used. The LEDs turned on, started blinking, etc.

Then I connected the TP-Link switch to a router, and the RPi 2 was connected to the network, got an IP, was able to connect to internet, etc. But if I connected it directly to the router again, I'm not able to get any connection at all again.

What could be wrong? I just can't imagine what could be causing this, could anyone help me out?

[pcmanbob]

Have you tested the cable that you used to connect your pi 2 to the router using the pi 1 .

Often faults like this are caused by one wire being disconnected in the cable.

I take it the tplink switch is a 10/100 device the same as you routers.

[LegendBR]

Tested with multiple cables, always the same results. And yes, all devices are 10/100 Mbps

[drgeoff]

Sometimes these strange happenings stop when the router is rebooted.

[LegendBR]

Sometimes these strange happenings stop when the router is rebooted.

Indeed, but unfortunately that didn't solve it