GH688,GA628, Standard Electrical Repairs
4/00021-2/FEA 209 544/1.G 28 (112)
* If the VANA voltage isn’t correct, proceed to chapter 3 (“Doesn´t start”-
fault).
* If VANA is correct, check the resistances of R830 (470 ohms), R825 (3.3
kohms) and C835 (>1 kohms, all of class A and in fig. 4.3).
• If the voltage at R825 is correct, check the resistances of C810 (>10 kohms),
C812 (>100 kohms), R802 (~3.9 kohms) and R805 (~15 kohms, all four of class
A and in fig. 4.3).
If the fault remains, send the phone to the next level.
4.6 Handsfree speaker out of order.
The fault is caused by an interruption somewhere in the audio path from the output
of N800 to the handsfree speaker (connected at the system connector). The audio
path is shown in fig. 4.7.
Fig. 4.7
Open the phone and check for liquid damages, especially around the system connec-
tor (X602) pads 1, 2 and 4 (fig. 4.5).
Measure the resistances of C850 (>100 kohms) and C851 (>1 kohms, both in fig.
4.3).
Make sure all the components shown in fig. 4.7 (R803, R804 and C813) are
mounted at the circuit board (fig. 4.3).
Check the solderings of N800 (fig. 4.3).
Measure the resistances of R803 (~100 ohms), R804 (~100 kohms) and C813 (>100
kohms, all of class A and in fig. 4.3).
Measure the resistance from the marked side of C813 to system connector (X602)
pad 1 (~0 ohms, fig. 4.5)
• If the resistance is too high there’s a foil damage and the phone is to be dis-
carded.
If the fault remains, use the schematics.
To Next Page
Loading...
