SH888, S868, Standare Electrical Repair
4/00021-2/FEA 209 544/3.D
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3 Doesn’t start.
3.1 Find out if the phone starts when pressing
the On/Off key.
Insert a fully charged battery into the phone and press the On/Off key.
•
If the phone doesn’t start, proceed to section 3.2.
•
If the phone starts when assembled but not in the troubleshooter fixture, check
the current consumption.
* If it’s more than 1.5A or as high as the current limit of the power supply,
then N401 (class D1, fig. 3.1) is broken and the phone can’t be repaired at this
level. Measure the resistance from N401 pin 14 to ground. It should be >10
kohms but if it’s approximately 200 ohms it means that N401 is broken.
Fig. 3.1
•
If the phone starts, check the charging function by connecting a charger at the
system connector.
* If it doesn’t charge, proceed to chapter 6 (“Charging”-fault).
Open the phone and make a visual check. The component side of the circuit board is
shown in fig. 3.1. Check for eventual liquid damages and burnt or damaged pads at
the system connector. Check R421 (~0.1 ohms, class B, fig. 3.1) and faulty solder-
ings at D600 and D610 (fig. 3.1).
•
If R421 is replaced, the charging function have to be verified using the method
mentioned in section 6.1.1.