User Guide

RH-26
7 - Troubleshooting Instructions CCS Technical Documentation
Page 32 ©Nokia Corporation Issue 1 02/04
Lights
The total amount of LEDs is 19 pcs: 3 inside LCD, 8 assembled to engine and 8 to flip
module. LCD and engine LEDs are powered from DC-DC converter D300 located under
the UPP shielding. LCD and function keys are always illuminated when D300 is switched
on. On/off control line is UIDRV(3) KLight. Engine side qwerty-LEDs have own switch
V350 controlled by UIDRV(2) DLight line. Both controls are driven by UEMK D200.
Flip LEDs are connected straight to VBAT. Both T9 and qwerty lights have own switch and
can be independently switch on and off by flip MCU.
Symptoms
No lights.
• Engine side (half-qwerty, function keys and LCD). D300 circuitry under UPP
shielding is faulty. Repair is not possible.
One or more LED blank.
• Check all LEDs and series resistors R311, R312, R313 and R314. If the engine side
qwerty-LEDs V311-V314 are blank, check switch V350, which is located under the
UEM shielding. Lights are on when DLight line (R305) is 1.8V.
Illumination failure LCD.
• Check LCD connector X300/pins 1,2. If OK, change LCD module.
Illumination failure flip, keyboard working.
• Change flip module.
Figure 13: Engine LEDs and series resistors