Hi there,

I've recently switched my installations to use RB750G's instead of RB450's, and I'm starting to see issues regarding power. Sometimes the routers do not start up when power has been plugged in - after waiting a while it works.
I've also seen routers that suddently loose power while running, and only pulling out all cables, including ethernet, makes it boot again.

Has anyone seen similar problems?

bad caps? can you open one and look?

Nothing visible.

What PSU you use?

The small 12V adapters that come with the routers.

Try with 24V; 0,8A PSU. RB750G power consumption is very close or more then 6W depend on RB state.

I think I've found the problem.
Somehow, if you plug the 750G Ether1 into a switch that runs PoE, the router blinks shortly when you plug in the PoE-running cable and when you plug in the cable, it won't start up.
Our PoE is the standard one, so it's not supplying enough voltage for the board to power up.

I am suspecting that this is also a problem if a PoE-cable is plugged into any of the other ports, but I cannot verify this yet.

RB750G support ether1 poe over spare lines and poe over data lines ( 24V non standard ) When you connect ether1 to POE swich ( tipicaly 802.3af with 48V POE ) RB goes to OVP state. Just don't use ether1 with swich with poe ports. Ether2-ether5 is simple gigabit ports without POE incoming or outgoing.

aaa's answer seems correct. I have read that ether1 also supports PoE. I have about 10 750G's in the field using the included PSU. I have not had any issues.