Phone Fails After Power On; Measurement Points At The Vcxo - Nokia RH-18 Troubleshooting Instructions

RH-18/38

Phone fails after power on

If the phone stops working a short time after the power is turned ON, a possible reason
for this could be that the 26MHz system clock signal is not getting to the UPP clock-
input in BaseBand. In this case check the following:
1 Turn on the phone and check
2 VCXO Power supply (C620) = 2.7V
3 VCXO output (R425 – end not
If this is not the case check the reference crystal (B600) and Mjolner (N600) as well as
R425, R426, C425, C426.

Measurement points at the VCXO

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connected to C425) is 26MHz and approx. 700mVpp
Figure 22: Measurement point for VCXO supply
Figure 23: Measurement point for VCXO output
Nokia Corporation.
CCS Technical Documentation
Issue 1 10/03