Panasonic SJ-MJ55GH, Service Manual

Page: 20 / 52

Main unit’s keys LCD display position and letters
After the second key is pressed, the first digit displayed
will change from “ ” to “O ”.
HOLD OFF
VOL+ After the second key is pressed, the second digit
displayed will change from “ ” to “O ”.
VOL-
After the second key is pressed, the third digit displayed
will change from “ ” to “O ”.
5. After all keys have been pressed and there is no abnormality, “E
OOO ” will be displayed.
6. Perform below voltage check about the keys come under if it is
not displayed “E OOO ”.
Main unit’s keys Check points ON OFF
IC201 48pin 0V 2.2V
HOLD TP428 0V 2.2V
VOL+ TP421 0V 2.2V
VOL- TP421 0.58V 2.2V
TP421 1.13V 2.2V
TP421 1.69V 2.2V
Note:
Refer to “12. Printed Circuit Board Diagram” for the test points.
7. Remove the battery when you exit from this mode.
7. Troubleshooting Guide