Troubleshooting
111707 Service Manual
14
4. Troubleshooting
4-1 No Power
Check Combo board and
combo harness
NO
Check U6 and
related circuit of U7
NO
YES
Does proper DC 5V appear at
pin2, pin3 of CN1
YES
Does proper DC 3.3V appear at
pin 4 of U1
Check U2 and
related circuit of U2
NO
YES
Does proper DC 2.5V appear at
Pin 4 of U2
Check X200 and
related circuit of X200
Replace Main Board
NO
YES
Does proper 14.318MHz appear
at Pin 102.103 of X200
YES
Check U201 and
related circuit of U201
NO
YES
Does proper signal ouput
appear at pin 139~142,145~156
of U201
Check U202 and
related circuit of U202
NO
Does proper signal ouput
appear at pin 13~21 of U202
