Ruim Card Flap Grounding; Rf Connector Failure - Nokia RH-77 Troubleshooting Manual

Nokia Customer Care

RUIM Card Flap Grounding

Conductive sticker
RUIM card flap
Figure 7: Conductive sticker grounding RUIM card flap to RF shield
The RUIM card flap needs to be grounded to the RF shield with a conductive sticker
(see Figure 7). If the sticker is damaged or missing, then the radiated sensitivity could be
reduced by 4—8 dB.
• If the conductive sticker is missing or ripped, replace the sticker.
If the RF shield needs to be disassembled from the chassis, the sticker may be damaged
because the sticker needs to be removed to change the antenna module or the RUIM
card flap.
• If you replace the RUIM card flap or RF shield, replace the type labels and
conductive sticker.
• You may need to replace the RF shield and all the labels because the conductive
sticker is located underneath other labels.

RF Connector Failure

The RF connector could fail by not connecting the RF input to the RF output of the RF
connector. If this happens, the antenna gain will degrade by about 25 dB. Check for this
by testing for DC conductivity between the RF input and RF output of the RF connector.
Note that the DC conductivity test must be done without any cables attached to the RF
connector. Because the RF connector is also a switch, the RF output is disconnected from
the RF input when a cable is inserted into the RF connector. When a cable is inserted, the
RF input is connected to the RF connector.
• RF input — connector to a duplexor
• RF output — connects to the antenna pad through vias
• RF connector — connects to a coaxial cable
If the RF input is not connected properly to the RF output, replace the RF connector.
Issue 01 04/2005
RF shield
©2005 Nokia Corporation
Antenna Description and Troubleshooting
Company Confidential
2118 (RH-77)
Page 7