Pioneer PDP-42A3HD Training & Troubleshooting Manual page 59

Basic Inspection
Mulfunction or Not Working of Remote Control Unit
Preliminary Checkpoints
Check the battery condition of the Remote Control Unit.
Check against the a set that works normally to see if the RCU (Remote Control Unit) is working.
Check whether the connector between Digital Board and DTT&Analog Board is connected. (JP701)
Note that DTT board does not receive the key directly from RCU. Instead, MCU of digital board
gets the keys and passes them to DTT through the UART0. (Pin 34 &35 of JP701)
Check the battery of the RCU.
Check the UART0_RX signal
Check signal line path to the
main CPU of DTT board
Mulfunction or Not
Working of Remote
Control Unit
Check the RCU.
OK
Check the connector
(JP701)
OK
Waveform 1 (When 'OK' key is pressed)
(Pin 33 of JP701)
OK
(U2)
NG
NG
NG
59
Replace the battery/RCU
Secure the connector
Check the digital board /
Check the IR & LED board
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