SH888, S868, Standare Electrical Repair
4/00021-2/FEA 209 544/3.D
24
(66)
4.10 Other audio fault.
Check the contact pads at the system connector for dirt, liquid damages and oxida-
tion. Replace the system connector if needed.
Open the phone and check for liquid damages, especially around the system connec-
tor pads.
Give the board power and start it up.
Check the VDIG and VDSP voltages (~3.2V, fig. 4.6).
•
If any of the voltages are incorrect, proceed to chapter 7.
Check the VDSPC voltage (~2.5V, fig. 4.6).
•
If it’s less, measure the resistance from it to ground (>10 kohms).
* If the resistance is too low, replace components in the following order:
C903 (fig. 4.6), C904 (fig. 4.6), C905 (fig. 4.6), R727 (fig. 4.1) and D900 (fig.
4.6, all of class A). Check the resistance from VDSPC to ground after every
component replaced.
* If the resistance is correct, replace V703 (class A, fig. 4.1).
If all the feed voltages are correct, check the solderings of D600 (fig. 4.4), D900
(fig. 4.6) and N800 (fig. 4.2).
Measure the resistances of R703 (~0 ohms, fig. 4.6), R693 (~0 ohms, fig. 4.1), C850
(>100 kohms, fig. 4.2) and C851 (>1 kohms, fig. 4.2, all of class A).
If the fault remains, send the phone to the next level.
