300c aka CSM randomly rebooting

I have a 300c aka CSM in TDD PTP as slave to a 1000GPS.   I'm trying to figure out if I need to climb Tower A and replace the CSM or if there is a known issue with AC CSM in PTP with N 1000GPS and I should climb Tower B and replace the 1000 with a 3000L .

So during a break in a storm several months ago we replaced a dead F200 on tower A (it was the slave PTP to a 1000gps). Turned out the new F200 had the 10dB chain imbalance defect and the window in the storm was about gone, I didn't have another one on hand.. it was working, mostly, we left it.

Fast forward to about 2 weeks ago we finally got back to this tower and replaced the defective F200 with a CSM in a RF Elelments Horn.  So now  300c slave on tower A , 1000GPS master on tower B. Everything looked good.

Then tonight the 300c suddenly started randomly rebooting (says Hard Reboot on counter). Longest it will stay up so far is about 34 minutes. 

The 300c was running 4.5rc52 (or whatever the current one is) and the 1000 Master was running 4.4.3. So I loaded 4.4.3 on the 300c and waited for it to reboot itself.   It reboots itself and comes back up with 4.4.3.

Just minutes later it reboots itself again.  I load 4.4.3 up again (so both banks will be 4.4.3) and wait.  About 30 minutes later it reboots itself again, comes back up 4.4.3 in both banks.   Then 17 minutes , reboots again. I load 4.4.1 and wait for it to reboot, shake rinse repeat , it and the 1000 Master are currently running 4.4.1  it's still rebooting randomly with 34 minutes currently the record for longest it's gone without a reboot.

I also tried changing the frequency to a non-dfs frequency.

Checked to make sure the SA wasn't running (it wasn't)

Locked down the MCS to 1 less than it was doing  (100% MCS7 - 64QAM 5/6 locked it to 6 - 64 - 3/4)

Disabled remote management 

Soft rebooted it

Finally drove out and replaced the power supply (it was being powered with the supplied cambium PS)

There is nothing in the logs , I downloaded a support file.


Could you please send Tech Support File to me?

Thank you

Sent the file over the weekend. 

Meanwhile the rebooting stopped about 4am the next morning and it hasn't rebooted for almost 3 days now.

1 Like

Hey Brubble,

Any news? 

I have a f200 that has been doing this, just randomly reboots. We changed power supplies, the radio, cable lpu. Its 200% a new install now. Never had an issue for 3 years, but suddenly it started happening. The client got a good ups, non-switching type, slowed down the reboots but was still getting 4 to 20 in a day. We do have a 10kw fm station 25miles away in a near path location but i have 6 others in a similar situation with no reboots. 

Recently we were back out to see what we could do, turned to point to another tower to use the dish as an rf shield against the fm station, and found a bite mark in the cable. Sure enough, touched it and the radio rebooted. 

I am not saying this is your issue, but it is sure one to look for!

The 300 csm continued to randomly start rebooting and stop rebooting so we replaced it a few weeks ago. New 300 csm hasn't rebooted since it was installed.


Can we get a one rebooting back to our office? We will send you the replacement.




  We started the RMA process on the CMS but I don't believe we have mailed it out yet (actually I think the person trying to RMA it is still in the "Have you tried rebooting it" stages with Cambium support".   Let me know what you want me to do with it or where you want me to send it.


Please give me the support ticket number and I will instruct our support team what to do.




The ticket number is below. Note that we started this ticket as  " f300 CSM  Radio is rebooting randomly & often."

That has somehow become :

Cambium Networks ticket 212699 update: ePMP Force 300 - No Power.

We are trying to RMA several radios and very much get the feeling of "Are these guys even reading what we are writing"  and I'm not entirely sure something didn't get confused here but they actually quoted "Radio is rebooting randomly & often." in their email about "F 300 - No Power"  so we think this the one for the rebooting 300 CSM.


So I got a RMA# from cambium support and there is no mention or indication that you or anyone reached out to them.  They ask that I reach out to the reseller we purchased the radio from to return it. Is this going to get the radio where you want it to be ?

Sorry for the delay. I spoke with support Thursday last week and they should have all the instructions.

You can post this thread in the support ticket as well.