WEMA (Kus Americas) Multi-Tank Level Indicator

[MFD]

I have one these as shown in the attached picture.
It is about 16 years old and a few days ago, it started just blinking the #7 light.
None of the buttons work.

I had some scheduled electrical maintenance anyway, so powered down the boat, and when power came back on yesterday it was working again.
Hooray!
Well, I looked this morning, and it is back to just blinking the #7 light and no response from the buttons.

I never had any trouble with this or the sensors other than cleaning the holding tank sensor every few years when it's stuck from build up.
These are in stock locally at Fisheries Supply and tomorrow I am going to unscrew and look at the connectors and stuff before just buying a replacement.

I thought would check in here if anybody has had a similar problem and if there is a fix or well known issue.

Thanks in advance.

 

[MFD]

To close this out...

I did power it down completely, powered back up and it was stuck on solid #5, then an hour so later when I looked it was blinking #7 again.
Picked up a replacement locally.
Install went well, one of the connectors on the newer model is slightly different, but it was supplied so easy to wire in.