Alfred (N750) Receiver Troubleshooting; Alfred Dc Troubleshooting - Nokia 6015 Troubleshooting - Rf

Nokia Customer Care

Alfred (N750) Receiver Troubleshooting

Keep the following under consideration when troubleshooting the Alfred (N750) receiver:
• There is a separate LNA for 800MHz (Cell and AMPS) and 1900MHz (PCS).
• There is a separate RFA (inside Alfred) for 800MHz (Cell and AMPS) and
1900MHz (PCS).
• After the RFA, there is a mixer and then the signals are separated by CDMA (Cell
and PCS) and AMPS.
For example, if there is no IF frequency (128.1MHz) check both Cell and PCS. If
there is only one at 128.1MHz (L753), ensure that IF_SEL is working. If it is, then
replace Alfred because of a bad RFA.
If Cell and AMPS are working but PCS is not, look at the band select line and the
PCS RF filter before replacing Alfred.

Alfred DC Troubleshooting

There are two common explanations for an Alfred failure consisting of high current in
Local Mode with just the RX turned on:
• No presence of an LO signal
• Input impedance drop is shorting out one of the DC supply pins to the chip
Issue 1 08/2004
6015/6015i/6016i/6019i (RH-55), 6012 (RM-20)
Cell
RFA
IFAs
LO
PCS
Buffer
RFA
Figure 32: N750 (Alfred) receiver
©2004 Nokia Corporation
Troubleshooting - RF
Cell
LNA
PCS
LNA
Company Confidential Page 39