Measurement Points For The Pll - Nokia NHM-8NX Series Troubleshooting Instructions

NHM-8NX
Troubleshooting Instructions
If the phone stops working a short time after the power is turned ON, a possible reason
forthis might 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 connected to C425) is 26MHz and approx.
700mVpp
If this is not the case check the reference crystal (B600) and Mjolner (N600) as well as
R425, R426, C425, C426.

Measurement points for the PLL

Measurement points at the VCXO
Page 42
Figure 22: Measurement point for VCXO supply
ãNokia Corporation
PAMS Technical Documentation
VCXO Vcc (C620)
Issue 1 05/02