Service Manual for SPICE series? (Dead 34C) (Repaired)

[Waon Shinyoe]

So I used a sand paper to expose the metal part from the FPC and soldered to the terminals (+ and -, there is another trace which I don't know where it connect).

When I inserted the batteries, the screen once showed 00000000 00, with no key response. After that, there is no display, even though there is power & clock signal.

Any idea what happened?