User Guide

RH-4 Company Confidential
BB Description & Troubleshooting CCS Technical Documentation
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TouchPad_LED
Are the display LEDs
working?
No
Change UI Module.
Are the LEDs
working now?
Retest failing
UI Module
Yes
Measure VLED+ and VLED-.
VLED+ = ~7.2V and VLED- =
~0.5V when LED driver
(N300) is enabled. Are they
OK?
(Notice: VLED+ = VBATT
when driver is disabled)
Change TP Module.
Are the LEDs
working now?
End
Retest failing TP
Module
Yes
Yes
No
Check N300, L300, V300, R300,
C303, C304 and C305.
If not OK, change defect part
Check X305 (solder
joints). Is it OK?
Change X305No
Are the Softkey LEDs
working?
Check X302 (solder
joints). Is it OK?
Change X302No
Yes
No
No
Measure VLED+.
VLED+ = ~7.2V when LED
driver (N300) is enabled.
Are they OK?
N
o
Check N300, L300, V300, R300,
C303, C304 and C305.
If not OK, change defect part
Yes
Retest
Yes
Yes
No