Chapter 1: Phone Does Not Switch On; 32.768Khz At C253; 32.768Khz At C254 - Nokia 6260 Repair Hints

Customer Care / Service & Support Readiness
Competence Transfer Team
Copyright © 2005 Nokia

Chapter 1: Phone does not switch on

Pre-check
Before any repair action, always check the current consumption of the phone: If it increases
directly to more than 0.5 ampere after connecting the phone to a service battery, most probably
there is a short circuit in the Vbat-line. This usually is caused by a defect power amplifier N700. To
verify carefully check whether N700 gets hot; or remove coil L700 and check the current
consumption again. If N700 gets hot or the current consumption lowers to normal values after
having removed L700, power amplifier N700 is responsible. Rework part with help of LGA rework
kit on a BGA rework system; do not forget to tune Tx values after N700 was changed!
On the other hand, if the current consumption is zero, especially check the battery connector X131
if bend or if the contact pins are stuck in the connector housing.
In case the current consumption remains around 50mA (please note that this value may vary
depending on your service equipment!), first you should try is to perform a software update.
Repair instructions
If the pre-check gives no further information about the fault, first of all check whether the
32.768kHz oscillator is working. Check signals at C253 and C254 with an oscilloscope:
In case no sinewave signal is measureable, check DC voltage at C253 and C254, both around 0.5V. If
the DC voltage is ok but no 32.768kHz signal is measureable, usually the crystal B250 is defect. If no
DC voltage is measureable at C253/254, most probably UEM D250 is defect. As UEM is underfilled, it
is not possible to exchange D250.
If the 32.768kHz oscillator is working, check function of power switch I301. The power switch is
located on the hinge flex, which cannot be put into the service jig. Due to that the power switch of
the phone itself cannot be checked. Only the voltage coming from UEME for the power switch that
is built into the service jig can be checked. In unpressed state the voltage level normally is ~4V, if
switch is pressed the voltage must decrease to 0V.
Therefore, if the module you are in doubt about switches on without problems in the service jig,
but does not work when connected to the hinge flex indicates that the hinge flex might be defect.
Exchange mechanical subassembly A4 and retest the phone.
If no voltage is measureable at the power switch, even when not in use, check mechanical
condition and solder joints of connector X817. If the connector is ok, most probably UEME D250 is
defect. As UEME is underfilled, it is not changeable.
Edited by:
TBE

32.768kHz at C253

Checked by:
SCCE
CONFIDENTIAL
03.02.2005

32.768kHz at C254

8 (21)
Repair Hints
Version 1.0 Approved
6260 / RM-25
Approved by:
MKO/PRZ