Firmware updated carried out on management board. Lost connection to UPS

[Andy5]

Hi there. Wonder if i could possibly have some help please.

I recently carried out a routine firmware update to the management card on our ups. Since then ive lost communication to said, UPS. With the message as

"Lost communication to the UPS"

The card is a UPS Network management Card 3

Ive tried all the usual thing, holding the reset button down and on friday night completely killing the power to the whole ups itself but the problem is still there...

Could anyone point to any fault finding i could start please.

Many thanks.

Andy

[Teken]

You’ll need to provide a lot more information regarding the problem. What APC UPS SKU is this?

What NMC 3 firmware was the system running prior and what did you install?!?! Provide a link to the UPS product page and NMC Firmware so there’s no mistake as to products and software in question.

Regardless of the above updating the NMC firmware is typically straightforward and very few problems are encountered (IF) all requirements are met.

Some of the basics are staged upgrade which means if the system was on 1.X.X than 1.X.X -> 1.5.X as an example. Going directly from say the oldest 1.X.X to 2.5.5.1 could result in issues.

Using the Firmware Upgrade Utility (FUU) is the recommended method via FTP and (NOT) SCP. Along with (NOT) saving logs from the system.

Upgrade must be done with an Administrator or APC Super User account. If the NMC indicates lost communication verify you’re using the correct NMC Firmware for whatever hardware platform such as Smart-UPS vs Symmetra Single Phase.

If you can still connect to the NMC provide what is stated under the About for both UPS / NMC.

The information can be obtained via SSH or Web interface.

Given the system is in a unknown state complete the format process before you proceed further.

Remove the Ethernet cable and insert a paper clip into the reset hole. Press and hold for 20+ seconds or when you see the right side LED turn orange and flicker than release.

You may also refer to this APC NMC FAQ:

https://www.se.com/us/en/faqs/FAQ000268950/

It will take approximately 60 seconds to format the NMC. Depending upon what firmware version it was on you’ll need to login via HTTTP or HTTPS.

If you can gain access then enable FTP. If the web interface doesn’t load then enable the same via SSH / CLI.

You can then proceed to use the FUU to upload the correct NMC 3 Firmware.

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[Andy5]

Hi there - thanks very much for the reply. Ive got access to telnet by plugging in a usb cable.

Below is a copy and paste from the top of the output from telnet.

Network Management Card AOS v2.5.0.8
(c) Copyright 2023 All Rights Reserved Easy UPS 1-Phase APP v2.5.1.7

The model is a Smart UPS SRT6000

There are 2 trays...the upper has 2 batteries and the Display - the lower tray has 4 batteries.

[Andy5]

Hi there - this could come up twice as i thought id posted but the  post appears to have disappeared....

Network Management Card AOS v2.5.0.8
(c) Copyright 2023 All Rights Reserved Easy UPS 1-Phase APP v2.5.1.7

The model is an Smart UPS SRT-6000 with 2 trays - the upper has the controller with 2 batteries and the lower holds 4 batteries.

Ive got access to the console over a usb cable (then telnet)

[Andy5]

Just also to add ive got ssh access too now also.

[Teken]

Format the NMC and report the outcome.

You’ll need to identify the new IP Address via router / firewall as the system will default to DHCP with the factory APC host name.

Web access by default will be via HTTPS. FTP will need to be enabled if you intend to use the Windows FUU Application. 

You haven’t confirmed what NMC this is and whether it’s embedded or Add-On via Smart Slot.

As the NMC could be a NMC 3, NMC 4.

Questions Ask . . . 👍

[Teken]

If this is a NMC 3 than you may download the latest 2.5.5.1 firmware using this link:

https://www.se.com/us/en/product/AP9641/device-monitoring-and-management-network-management-cards-nm...

Insure you select the Smart-UPS version! Based on the information you provided it appears you used the Easy-UPS NMC Firmware version.

[Andy5]

Hi there - i ran the format last night from the ssh session. I can still sign in over ssh but it has retained the fixed ip. I can get to the web server part but i cant see in there where to flash the firmware (probably because its lost connection to the UPS maybe?) I click on the link its doesnt appear to be exactly the same as mine as mine isnt a removable card....

 is there a procedure to flash over ssh or telnet/serial as i have the ability to do both at the moment. Thanks very much for your reply. Very helpful.

[Teken]

You may refer to this APC NMC FAQ:

https://www.se.com/us/en/faqs/FA156047/

Ensure you confirm what NMC Hardware is in place. Once known you can download the software applicable for the NMC firmware and use the FUU.

Using that method requires FTP to be enabled. If you intend to use SSH / CLI or XModem / Terminal to send the individual files insure you send the boot monitor file - first.

Then, AOS -> Then Application Module.

As stated in the FAQ you’ll need to wait for each file to install before proceeding to the next file.

Questions Ask . . . 👍

[Andy5]

Ok - a little bit lost now.

1. Im not sure how to verify the NMC firmware as its not working on the board (reason im here) and that version in the ssh out put is all i can see. (2.5.0.8) which we think is wrong?

2. The hardware ive take the pic of and the model SRT6000 isnt enough to identify what it is? Im not sure what else to look for.

3. SSH'd in and tried to enable the ftp using every known command line variation and it wont enable....it did say it did enable, rebooted and went back to disabled...

4. Assuming ive got the right firmware youve stated i have to wait for each file to install? ive only got one file called apc_hw21_su_2-5-5-1.nmc3 in the bin folder - even if thats the right place.

Apologies for being a bit thick.!

[Andy5]

Hi there. I took a bit of a punt which seems to have paid off. Its now working again. I was quite sure that i had the correct firmware as it stated that it was for the SRT range. I used the NMC firmware utility using the SCP protocol and sent the enclosed file over...in that i just hit "Start Update" so its now back up so i can replace the batteries. One question is that ive got the 3 errors.... just to confirm the internal pack cartridge 1 is the left hand battery and below on the Battery tray that would be the right hand 2 batteries.

Finally many thanks for all of your help. Im almost there.

06/17/2026	03:32:58	UPS: Battery life exceeded. Order replacement battery, APCRBC140, for battery pack 1, cartridge 2.
06/17/2026	03:32:57	UPS: Battery life exceeded. Order replacement battery, APCRBC140, for battery pack 1, cartridge 1.
06/17/2026	03:32:57	UPS: Battery life exceeded. Order replacement battery, APCRBC140, for the internal pack, cartridge 1.

[Teken]

If you’re sure the NMC is indeed a NMC 3 you can follow the NMC FAQ relating to sending just the single file via XModem.

In older generations NMC 1 / 2 the individual files such as Boot, AOS, Application needed to be sent individually. 

As such the individual files were present. This isn’t the case for the NMC 3 / 4 running the latest firmware branch.

You’ll probably need to use the Serial Console (Micro USB) port to connect and upload the firmware using a terminal program if you can’t enable FTP / SCP to use the FUU.

Cost you nothing to try the Windows FUU software application to see if the firmware can be sent via SCP.

If that doesn’t work then you’re obviously limited to using the serial console port with the APC Proprietary Micro USB Cable! 🤢

Questions Ask . . . 👍

[Teken]

You will need to show me a photo of the entire system with the front bezel taken off.

Normally the main system is Pack 1. Which has two RBC cartridges 1 & 2. Both must be replaced during a RBC replacement as both pairs make up the 192 VDC system.

If the system has extended battery packs they would be Pack 2, 3, 4 etc. Each extended battery packs will also have two RBC’s that must be replaced in pairs if they are EOL.

The serviced life of the RBC is 2-5 years based on usage, temperature, and environmental conditions. The raw cells that make up the RBC are designed to sustain 260 cycles subjected to the same caveats.

Once the RBC have been replaced insure you complete the following action items in sequence:

Date: The battery installation date can be changed via LCD, NMC, Power Chute. Doing so resets internal counters and adjusts charging tables if applicable. 

Self Test: Once the RBC indicates 100% SOC. Manually initiate a self test via LCD, NMC, Power Chute. Once passed wait for the RBC to recover to 100% SOC.

Calibration: This procedure will need to be scheduled during a maintenance window to reduce the impact on the business. 

Manually initiate a battery calibration with a minimum of 30% connected load or higher. Doing so will help the system learn the current battery health and better reflect the operational runtime via LCD, NMC, Power Chute, SNMP.

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[Andy5]

Front pic enclosed.

 So with regards to the date - thats the only way of applying the health of a battery? in that, theres no way of taking a battery plugging it into the system and being able to "read" the health - (is there any intelligence embedded into the battery) - like a laptop for example?

Currently running the self test at the moment. Ill wait for that to complete the proceed with the calibration.

Thanks very much for the continued help.

[Teken]

The vast majority of APC lead acid RBC only incorporate a fuse.

Some larger units incorporate a crude EEPROM chip to inform the main system the presence, counter service life.

Only lithium based RBC incorporate a BCM.

As it relates to which RBC you can simply disconnect the Anderson connector pairs and wait for the system to declare a RBC fault.

You can then determine which pack / cartridge requires replacement. In previous generations the pack / cartridge was marked on the housing is this not the case now?!?!

Questions Ask . . . 👍

[Andy5]

Hi there. Apologies for not replying back. I ordered another set of batteries for the internal tray which ive just replaced. Now those are in (plugged in and in the web interface put in the date installed)

I tried carrying out a calibration test which failed with this result...i looked in the event log but couldnt see anything. As this thread is now digressing a little bit would you like me to open a new thread?

Thanks.

Calibration

Refused

06/25/2026

management device

state of charge not acceptable

[Teken]

Generally speaking a battery calibration will not start or complete if the following conditions are present / not met.

The RBC must be at 100% SOC. The calibration must be done with a minimum of 30% connected load or higher. 

A battery calibration must be performed when a new RBC is installed especially when they are in pairs. Calibration should be conducted sparingly as this process goes against the 260 cycle life of the raw cells.

NOTE: In some instances where the system continues to (Think) and display anything but 100% SOC. 

Battery calibration must be performed manually by removing AC Mains from the wall outlet during a scheduled maintenance window.

All critical loads must be removed / powered down and replaced by any resistive load.

Any USB / Serial cables that connect to Power Chute shutdown software must be disconnected. 

Once the UPS shutdowns reconnect AC Mains and allow the RBC to fully charge to 100% SOC.

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