Fm Radio Troubleshooting Setup; Fm Radio Part Layouts And Probe Points - Nokia 6235 Troubleshooting Manual

6235/6235i/6236i (RM-60)
RF Description and Troubleshooting

FM Radio Troubleshooting Setup

Use the following steps to troubleshoot the FM radio while using a Pop-port headset.
1. Connect the Pop-port headset (HDS-3) to the Pop-port connector (bottom
connector).
2. Select the Menu > Media > Radio from the mobile terminal user interface.
3. In an FM radio broadcast coverage area, set a local radio channel by scanning
automatically using the Automatic tuning option. (Scanning up and down the
channels by pressing the "Up" and "Down" key respectively).
4. If no channel could be found, inspect all the components in the FM radio
circuitry.
• If the circuits pass a visual inspection, check the existence of the LO (by
radiative pickup) near the VCO of the FM Radio IC.
• If no LO is found, replace the FM radio IC.
5. Listen for sound out of the headset.
• If there is a signal present, continue to step 6.
• If there is no static sound present, inspect all FM Radio circuits on the PCB
and refer to the "Audio" section of the Baseband Description and
Troubleshooting chapter for more information.
6. Disconnect the Pop-port headset and connect the universal headset to the UHJ
(top connector).
7. With the universal headset connected, repeat steps 1—5.
• If there is a signal present, the FM Radio is working properly.
• If there is no static sound present, refer to the "Audio" section of the
Baseband Description and Troubleshooting chapter for more information.

FM Radio Part Layouts and Probe Points

Use the following values when probing the LO near the VCO of the FM radio IC (N6100).
See Figure 68
Description
LO frequency
IF frequency
For example, if the Rx frequency is 87.5 and the IF frequency is 225kHz, the LO equals
175.45MHz [(87.5+0.225)*2 = 175.45MHz].
Page 66
for the location of the N6100.
Table 9: FM Radio Test Point Values
©2005 Nokia Corporation
Value
(Rx frequency + IF frequency) x 2
225kHz
Company Confidential Issue 1 04/2005