Remove CP off the prcessor.
Remove top cover unscrewing 4 screws at corners (back side) and 2 nuts from the DB9 pin plug.
Remove flex keypad plug off the pins.
Short cut for a second (use 100 Ohm resistor, not a wire) pins 2 and 4 (counted from the bottom, display window should be on top and face down for proper countdown).
You have corroded flat silver wires at flex keypad, broken close to the plug.
To fix that problem you can restore the contacts/wires using Car Rear Window Heater repairing glue (available at any autoparts store)
Rgds
Remove top cover unscrewing 4 screws at corners (back side) and 2 nuts from the DB9 pin plug.
Remove flex keypad plug off the pins.
Short cut for a second (use 100 Ohm resistor, not a wire) pins 2 and 4 (counted from the bottom, display window should be on top and face down for proper countdown).
You have corroded flat silver wires at flex keypad, broken close to the plug.
To fix that problem you can restore the contacts/wires using Car Rear Window Heater repairing glue (available at any autoparts store)
Rgds