SH888, S868, Standare Electrical Repair
4/00021-2/FEA 209 544/3.D
14
(66)
Fig. 3.2
Check the amplitude of the 13MHz system clock at B510 pin 1 (~1V t-t, class C, fig.
3.1). Measure it by using an oscilloscope, spectrum analyzer, frequency counter or a
diode probe.
•
If the amplitude is too low, send the phone to the next level.
Make sure there aren’t any faulty solderings at D600 or D610 (fig. 3.1).
•
If it looks good, replace D600 (class B) first and then D610 (class A). Note!
Don’t replace any of the circuits unless you’ve established the fact that B510 is
functional. Try programming the phone in between.
3.4.2 The phone is programmable but doesn’t start
afterwards or the phone is troublesome in the
flash programmer.
Open the phone and check for liquid damages.
Make sure the system connector pads aren’t damaged or burnt.
Measure the resistance of R421 (0.1 ohms, class B, fig. 3.1).
•
If R421 is replaced, the charging function have to be verified using the method
mentioned in section 6.1.1.
* If it still is incorrect, send the phone to the next level.
Mount the board in the fixture. Start it up and keep it running by keeping DCIO
high.