Main Display Failure - Motorola APX 1000 Detailed Service Manual

5-22
5.5

Main Display Failure

No Display
Replace LCD
Problem still persist?
No
Check DC on following
Signal Probe Point
V_Ext_1.86 TP2005 on keypad
V_2.775D TP2008 on keypad
Is 6 < V < 9
No
Check U6504 circuitry.
Yes
End
Check the following signals:
Signal
Yes F_DISP_RW
F_DISP_DATA_CMD
F_DISP_RW_EN
OMAP_RESET
Troubleshooting Charts: Main Display Failure
Probe Point Level
R2135 0V
R2147 1.85V. Hi = Data. Low = Command
R2142 1.85V. 4MHz Square
OMAP_RESET_TP 1.85V
Signals
Correct?
Yes
Verify connectors from J2302 to
front kit flex.
Connectors
Good?
Yes
Replace chassis subassembly
Check U6302 and U6101
No
display lines. Change faulty
part.
No
replace board or flex
with bad connector