Display; How The Display Works; Display Troubleshooting - Nokia 3155i Troubleshooting Manual

3155/3155i (RM-41), 3152 (RM-61)
Baseband Description and Troubleshooting

Display

How the Display Works

Nokia 3155/3155i/3152 has a large main display (160 x 130 color depth), controlled by
the D2800 engine through a parallel interface. The secondary, black and white display
(96 x 68) is controlled by the D2800 engine through a serial interface. The UEMEK
powers using VIO and VFlash1.
Main display:
262K color (128x160)
Secondary display:
Black & White (96 x 65)
4-way navigation
key with center-
select

Display Troubleshooting

When troubleshooting the display, make these common checks (see
• Check that the display is connected properly and is making good contact with
LCD connector. If no display, replace the LCD.
• Check the power supply VIO and VFlash1. If not correct, check the UEMEK.
• Check the activity on the LCD test points. If no activity, check or replace D2800
• Check the parallel interface (DIF) for the main display
• Check that the DIF CLk is 4.8MHz
• Check the serial interface (LCD) for the secondary display
• Check that the LCD CLk is 2.4MHz
Page 20
Soft keys
Figure 18: Nokia 3155/3155i/3152 UI Display
©2005 Nokia Corporation
External keys
Volume key
UHJ Headset jack/
sliding cover
Company Confidential
Push-to-Talk key
Figure 19):
ISSUE 1 07/2005