User Guide

6015/6015i/6016i/6019i (RH-55), 6012 (RM-20)
Troubleshooting - Baseband Nokia Customer Care
Page 24 ©2004 Nokia Corporation Company Confidential Issue 1 - Revision 002 09/2004
to separate inputs at the UEM. Inputs for the microphone signals are differential types.
Also, the MICB1 is used for MIC1, and MICB2 is used for both MIC2 and MIC3 (Universal
Headset).
The HF single-ended output from the UEM is sent to the input of the MIDI audio
amplifier. VBAT supplies the voltage for driving the amplifier, which can be enabled or
disabled by the UPP using GenIO (10).
Display and Keyboard
The phone uses LEDs for LCD and keypad illumination. There are three white LEDs for the
LCD and two blue LEDs for the keypad, which is a separate board for the UI.
The phone also includes a 96X68 color LCD. The interface utilizes a 9-bit data transfer
and is similar to the DCT3-type interface, except the Command/Data information is
transferred together with the data.
Figure 16: D/C bit set during each transmitted byte
BB Test Points
Following are the top and bottom views of the BB test points, regulators, and BB ASICs.