# HG changeset patch # User Michael Spacefalcon # Date 1385942396 0 # Node ID 2bc45eb8818deb13ceec060cc35749578fcbd5f7 # Parent 1e797f846563026e8319e5312741c55464992f79 Pirelli PCB RE: attempt to trace out KBC/KBR lines stopped by grind-down damage diff -r 1e797f846563 -r 2bc45eb8818d pirelli/keypad --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/pirelli/keypad Sun Dec 01 23:59:56 2013 +0000 @@ -0,0 +1,27 @@ +Seeking to understand the 16-pin interface between the main PCBA and the keypad. +Both connectors (the one on the main PCBA and the one on the underside of the +keypad) have silkscreen with pin numbers around them, but the numbers in these +silkscreen labels don't match: per the main PCB silkscreen, pin 1 is toward the +edge of the phone, whereas per the keypad underside silkscreen, pin 1 is toward +the middle. + +Here I will use pin numbers per the main PCBA silkscreen. + +Geometric centre of the footprint is at (3923,456) in steve-m's L8 scan. + +Pin 8: connected to massive copper flood, almost certainly GND. + +Pin 9: connected to a copper fill that's islanded by some traces, so it may or +may not connect the same massive fill (GND?) as pin 8. In this island there is +a largish solid-connect via at (3915,475) and two smaller ones at (3766,539) +and (3911,507). On L7 these vias connect to massive copper flood - definitely +GND. + +The keymap given in OsmocomBB (confirmed to be correct) indicates that the main +keypad ought to use KBC0 through KBC3 and all 5 KBR lines. The 3 side buttons +use KBC4 and KBR1 through KBR3. Let's try tracing the KBC and KBR lines of +interest from the Calypso. + +Tracing KBC0, Calypso ball N4: goes to via at (4122,380). Found it on L2, goes +to a larger via at (4130,444). Found it on L7, trace disappears into the edge +grind-down damage.