7. GENERAL INFORMATION
7.1 DIAGNOSIS
7.1.1 TROUBLESHOOTING
A
Image for the composite or S signal is not displayed
Image for the composite or S signal is not displayed No Is the function corresponding No Select the corresponding to selected signal input signal with the Input selector. selected? Yes
B
TV signal is not displayed on the screen. Yes Is the Input selector set to TV? Yes Is a signal output normally from the FE (U7501)? (18) Yes Has the signal arrived at IC8002? (63) 2 Yes Check around the FE and No check the communications between the FE and the microcomputer. No Check the communications between U7501 and IC8002. No Set the Input selector to TV.
Has the signal arrived at IC8002?
No Check the communication between the jack and
B
Yes
IC8002.
1
B
B
C
Which signal is not output, main or subsignal? Main signal Is a signal output from IC8002? (44) (47) 34 Yes
D
Subsignal
Check around IC8002 and No check the communications
No
B
between IC8002 and the microcomputer.
Is a signal output from IC8002? (56) (58) 56 Yes
B
No Check the communications between IC8002 and IC6255.
Has the signal arrived at IC6107? (52) (59) 78 Yes
A
No Check the communications between IC8002 and IC6107.
Has the signal arrived at IC6255? (52) (59) 9 10 Yes
A
Is the communication No Check around the IC that is between each IC on the found to have a failure in MR MAIN BOARD Assy and communication and the the microcomputer normal? microcomputer. Yes
E
Has the symptom been settled when the MR MAIN BOARD Assy is replaced? Yes
� For check the communication with the microcomputer, refer to the section 6.7 SERVICE FACTORY MODE. � The encircled numbers denote measuring point in the Waveforms for Troubleshooting.
