Nokia N81 Service Manual

Backup battery troubleshooting
Verify that the backup battery is empty (U<1V). Switch the phone on. Measure voltage of the battery when
the main battery is connected to the phone and the phone is switched on.
Wait a few minutes and monitor that the backup battery voltage rises. Switch off the phone, disconnect the
main battery and monitor that the voltage of the backup battery decreases. Normal behaviour of the voltage
is described in the figures below.
Figure 15 Charging backup battery
Figure 16 Discharging backup battery
If the voltage rises and falls quickly, check whether either G2200 or C2233 is broken or short-circuited. Backup
battery can be also dead. If the voltage stays ~0V, check resistance VBACK against GND. If there is no short
circuit, AVILMA is faulty. Replace AVILMA.
RM-179; RM-223
Baseband Troubleshooting
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Nokia N81 Specifications

General

Display diagonal	2.4 \
Display resolution	240 x 320 pixels
Display number of colors	16.78 million colors
Ringer type	Polyphonic
Internal memory	8196 MB
Front camera type	Single camera
Rear camera resolution	1600 x 1200 pixels
Personal info management (PIM)	Alarm clock, Calculator, Calendar, Notes, To-do list
Headphone connectivity	3.5 mm
USB 2.0 ports quantity	1
Text prediction system type	T9
Multimedia Messaging Service (MMS)	Multimedia Messaging Service (MMS) is a standard way to send messages that include multimedia content to and from a mobile phone over a cellular network
Form factor	Slider
Product color	Brown
Gaming time	6 h
Browsing time	5 h
Talk time (2G)	4 h
Talk time (3G)	3 h
Battery capacity	1050 mAh
Standby time (2G)	1020 h
Continuous audio playback time	11.5 h
Continuous video playback time	4.5 h
2G standards	GPRS
Data network	wcdma
Bluetooth version	2.0+EDR
Bluetooth profiles	A2DP, BIP, DUN, FTP, GAP, GOEP, HFP, HSP, OPP, SPP
SIM card capability	Single SIM

Weight and Dimensions

Depth	102 mm
Width	50 mm
Height	17.9 mm
Weight	140 g