SRT5KRMXLI NMC firmware recovery and latest version

[Gooses]

I have an SRT5KRMXLI (APC Smart-UPS On-Line) that the firmware update failed on and now has no web interface. The forum post I followed (which I've now lost) said that the 704 updater was the correct one for this model - possibly this was not the case.

When I attempt to connect to the web UI, I get an "The Application Was Not Able to Load" message. I can log in via telnet which presents me with an AOS v6.7.2 interface, and I can see that there is still a apc_hw05_aos_672.bin present.

Please can someone suggest:

A) How I can restore the web interface functionality

B) How I can find the latest supported firmware for the device?

Many thanks!

[Gooses · Accepted solution]

I found the required help guide, more by good luck than good judgement:

https://www.apc.com/us/en/faqs/FA293874/

It did require purchasing of a serial to 2.5mm jack converter which is possibly the most obnoxious interface cable ever, but at least it's working again.