That's weird as normally the screen on those just gets progressively dimmer until you have nothing.
Although I have had similar problems with Chinese LCD's with the fluorescent back light.
It seems to start with pressing the light button, the screen goes all Egyptian hieroglyphic.
Never to return properly. Which is sad as this happened to my Josh Chadwick just last week.
Although unlikely the only common note is they don't get a lot of wrist time.
As for the reset spots I just cross them using the end of a flat screwdriver.
There's no secret formula (I don't think) just short the contacts together once, has always worked for me.
Hope you have more fortune than me, let us know if you sort it.
Sorry I can't be of more helpful, lets hope someone else has an answer.
Pete