Uhf Synthesizer - Nokia RH-77 Troubleshooting Manual

2118 (RH-77)
RF Description and Troubleshooting

UHF Synthesizer

Following are possible causes for an incorrect UHF frequency:
• Orientation of N601
• Power supplies to N601 PLL are missing or low (VR7)
• Loop filter components are missing or incorrectly installed
• Matching components to N601 TxLO/PLL input are missing or incorrectly
installed
• 19.2MHz reference clock is missing or low
• Programming is incorrect
• Component failure (VCO or PLL portion of N601)
Figure 29 and
Figure 29: (Top) PWB. (Bottom left) A zoomed view of the testing points on the UHF synthesizer layout.
(Bottom right) A zoomed view of the UHF synthesizer layout with part numbers.
Page 38
Figure 30 show the UHF synthesizer layout.
©2005 Nokia Corporation
Nokia Customer Care
Company Confidential Issue 01 04/2005