Ericsson I 888 Trouble-Shooting Instruction page 19

VDSPC is too low, then measure the resistance to ground. If the value is lower than
10 kOhm, then replace, one by one and check the resistance between, C903 (Fig
4.6), C904 (Fig 4.6), C905 (Fig 4.6), R727 (Fig 4.1) and D900 (Fig 4.6), all of them
are class A. If VDSPC is too low and the resistance to ground are larger than 10
kOhm, then replace V703 (class A, Fig 4.1). If the feed voltages are correct, then
check the solderings on D600 (Fig 4.4), D900 (Fig 4.6) and N800(Fig 4.2). If the
solderings are correct, then first replace D900 (class A, Fig 4.6) and try again. If that
didn´t help, then replace D600 (class B, Fig 4.4). If the fault still remains, send the
phone to next repair level.
C904
C903
D900
C905
4.9 Music mute fault.
Check the connection surface at the system connector. If they are fine, open the
phone and check for liquid damages, especially at the system connector pads. Check
the solderings on D600:69 (Fig 4.4). Measure the resistance of R602 (470 ohm,
class A, Fig 4.1). Measure the resistance MUTE (Fig 4.5) to ground. If the resist-
ance is lower than 100 kOhm, then replace F606 (class A, Fig 4.1). If the resistance
is correct, then replace D600 (class B, Fig 4.4). If the fault remains, send the phone
to next repair level.
4.10 Audio fault.
Check the connection surface at the system connector. If they are fine, open the
phone and check for liquid damages, especially at the system connector pads. Power
up the borad. Check VDIG and VDSP (both should be 3.2V, Fig 4.6). If any of the
voltages incorrect, proceed to chapter 3 ("Doesn´t start"-fault). Check VDSPC
(Should be 2.5V, Fig 4.6). If VDSPC is too low then measure the resistance to
ground. If the value is lower than 10 kOhm, then replace, one by one and check the
resistance between, C903 (Fig 4.6), C904 (Fig 4.6), C905 (Fig 4.6), R727 (Fig 4.1)
and D900 (Fig 4.6), all of them are class A. If VDSPC is too low and the resistance
to ground is larger than 10 kOhm, then replace V703 (class A, Fig 4.1). If the feed
4-00021-2/FEA 209 544/5.C
I888, Standard Electrical Repairs
VDSPC
R703
VDSP
Fig 4.6
VDIG
19
(42)