Self-test on APC Smart-UPS (SMT750) not completing

[BillP]

About two weeks ago, two of my APC SMT750 Smart-UPSs would start their scheduled self-test but would not seem to complete. They have the AP9630 NMCs. The NMC cards were one version 6.6.4. IThe two SMT750 UPSs are on firmware version UPS 07.1 (both UPSs have ID 17). I have an SNMP server, and the basic output status data that it gets from the UPSs say that they are onBattery (3). When I login to their NMCs, the home page says "UPS self-test in progress". The event log says that the test started, but no event saying that it completed. To clear the problem, I need to reboot the NMC cards. After rebooting the NMC, the NMCs' home page says "UPS is online" and the SNMP basic output status data changes to the correct value (2/battery is online).  In addition, when I go to the NMC web page's Tests->UPS and then run "UPS Self-Test", the top of the page says:

Test	Result	Date	Source	Cause
Self-Test	In progress	05/14/2020	Refused	management device

Nothing seems to happen, and the NMC Home page still says "UPS is Online in Green Mode". 

So, basically 2 problems:

1. The automatically scheduled self-test (every 2 weeks) doesn't seem to end (or more accurately, the NMC thinks UPS is still running the self-test when I don't think it's running.

2. Initiating a UPS self test manually doesn't seem to do anything.'

I upgraded the two NMC cards to 6.8.0 (latest version). Same problem.

I have a 3rd APC SMT750 UPS. It is on NMC firmware version 6.8.0. However, the UPS is ID 18 with firmware version 09.4. This 3rd APC SMT750 does NOT have the problem that the other two APC SMT750a have.

Any suggestions?

[bimmerdriver · Accepted solution]

Have you tried removing the NMCs from the UPSes? It would be useful to see if the self-test passes with the NMCs removed. Also, try to swap the NMC from the UPS that's not exhibiting the problem to see if the problem lies with the UPSes or with the NMCs.