Hmm, after reflowing some points (and moving that capacitor I had mounted on the bottom of the board to the proper place on top), the display still won't light up.
I understand it's very dim when the clock first starts and you're supposed to set the brightness manually... but it's not dim, it's just... not even on. Turned the room lights off and I didn't see anything.
But I did notice something, when holding the PCB to unplug the power from the jack, the PCB felt quite hot. Around the LM7805C chip. Could it be the fuse heating up?
The new converter I'm using is as close as I can get to 9 volts @ 1000mA, it's 12v at 1250mA. The 9v converters I have laying around are AC or don't have enough power to operate the clock.
I tried cutting the connector off the 12v and putting it on the 10v, but it wouldn't beep when I did that (verified polarity too), so, dunno.
It might be blurry, but this was the best I could get of the C1 capacitor I moved.
This area of the PCB gets very hot after being plugged in. Could it be because the converter is sending it too much current?
Reflowed these points, they look somewhat like the diagram you linked.
However, the display still remains inactive. Not even dim, it's like it's not plugged in or anything. Perhaps the fuse is shutting off before I'm able to see anything on the display?
Edit: meant to say mA instead of Ah.