Nokia Customer Care
RM-12
Issue 1 11/2004
Copyright
©
Nokia. All rights reserved
Page 94
USB Problems (2)
Measure
voltage V33 at
C2005
Incorrect
voltage
Correct voltage
Measure
USB+ (pin #6)
and USB- (pin
#7) on X2021
with
oscilloscope
No
toggling
Toggling
Measure
voltage VBUS
at C2006 when
connecting the
USB cable
Incorrect
voltage
~5V
Change USB
regulator N2001
and capacitors
C2005-C2007 and
resistor R2004
Check APE
GPIO3 from
R2004, ~2.8V
No
Yes
PC recognizes
the phone as
USB device?
Yes
No
Replace
EMI filter R2003
PC recognizes the
phone as USB
device?
Go to OMAP1510
troubleshooting
No
End
Change L2002,
PC recognizes
the phone as
USB device?
Yes
No
End
Go to OMAP1510
troubleshooting
Yes
End
Continued from
USB
troubleshooting
page 1
Measure
resistance to GND
from D+(pin #6)
and D-(pin #7) on
X2021 .
>> 1M?
Yes
No
Voltage levels
~0V and
~3.3V
Check R2004
value.
Undamaged
Change
resistor. PC
recognizes the
phone as USB
device?
No, but
APE GPIO3
~V28
Damaged
No,
APE GPIO3
still 0V
Yes
End