I know my 436 definitely has a dim display. I filled out the Repair Campaign signup, even though I have no idea if I have the RTC issue, based upon the fact that i need the dim display fixed.
I don't know what Uniden's position is on the matter, but I was in the same boat. I didn't realize how dim my display really was until I tried to make it brighter thinking I had lowered it. Then I found this thread and wondered if my 536 was going to have the same battery issue (Its on almost 24x7 on my desk)
So I started trying to make it happen. I'd shut it off for 2-3 days and try to let the battery drain, or I'd turn it off at night, turn it on in the AM, etc. I couldn't make the clock fail, period. So I gave up and went back to waiting.
Then the latest firmware updates came out and I started playing around with expanding my programming and pushing updates to the scanner. I unplugged the USB cable from the laptop to make the scanner reset and instantly - clock issue.
I don't know if its because the newest firmware is doing some different level of behavior with the battery check (they wrote new code that times out if the clock isn't set) or if it was just a pure coincidence, but I now have a dim display AND a radio that complains about the RTC every time I turn it on. If you've not done so, maybe update the firmware and try to connect Sentinel to it with a USB cable a couple times. Maybe you'll trigger something.
I submitted 5976 8 days ago. Still waiting but I'm in no rush, the scanner functions.
Jeff