SCP SCIENCE DigiPREP Jr. - Keypad Diagnostic Section; Entire Row or Column Problem

KeyPad service manual
Rev.1.1
21
o Press the LEFT ARROW key a couple of time and see if the cursor
switched from ON to OFF and so on.
o Press the RIGHT ARROW key a couple of time and see if the
cursor switched from ON to OFF and so on.
 Select HEATER OFF and press ENTER (Make sure that a DigiPREP is
connected
 Enter a time scale of 1 minute and press enter
 Press the ALARM, TARGET TEMPERATURE and TARGET TIME button one
at a time and verify if they are correctly doing what they are supposed to do:
o ALARM: A small “AL” should appear on the LCD display.
o TARGET TEMPERATURE: The target temperature menu should
appear.
o TARGET TIME: The target time menu should appear.
3.2 KeyPad Diagnostic Section
3.2.1 Entire row or column problem
 If all buttons in a row or column are failing, with the helps of figure 9, identify
the corresponding pull-up resistor.
o Remove the CPU board from the main PCB
o Measure with a multimeter the value of the corresponding resistor.
o If it is 4.7K, try to verify the connection (soldering) between the
VCC and the resistor.
o Then check if the resistor is also connected to each button
corresponding to its row or column (see figure 10 for resistors
location)