CMM 4 stopped powering AP's

I've been using a CMM4 for the last 2 years. Just yesterday it stopped powering the AP's. The power supply is showing 30 volts and there are lights on the "cmm mother board". I by past the cmm using a POE and the ap's run just fine. Has anyone heard of this happening or any way to fix this without having to buy another one?

I have not heard of this happening before.  Was there a surge or other ESD event or near-miss lightning recently?

It sounds as if the voltage output of the CMM board itself stopped working.

If the CMM4 is no longer in warranty, there are several folks out there that will perform repairs on such boards.

we have had this before and ended up being a short in the gps card. once we removed the GPS card it was fine.

I appreciate that this is an older thread, but a couple weeks ago we were going through our pile of "dead" CMMs.

We had two "dead" CMM4s that showed similar symptoms - partial power to the switch, none to the AP, or other similar power-related issues. The CMM4 has two +29V inputs - turned out the first was dead! Running fine on the other feed.

Old thread, new answer.

Not discounting the above answers as they are good testing solutions, but here is something to look for too.

On the cmm3 and micros there is a smd that looks like a resistor marked 0 near the 29v connections.
This is used as fuse. You can test this by using a multimeter and looking for the same voltage on both sides of it. If there is no voltage, than simply replace and the board works again. This fuses blows easily with lightning events.

I have not had a dead cmm4 or 5 yet so do not have an answer for them.