Ericsson I 888 Trouble-Shooting Instruction page 22

I888, Standard Electrical Repairs
age and the phone has to be discarded. Check VDIG on R620 (2,2 kOhm, class A),
if it is lower than 3,2 volt proceed to chapter 3 ("Doesn´t start"-fault). If the things
above are correct replace D600 (class B).
Is ground and should be 0 volt.(Measure the resistance to another ground point.)
VDLCD: If the value is incorrect, measure the resistance between the pad and
D600:45, it should be 0 Ohm. If it is correct, measure the resistance between the pad
and ground it should be larger than 2,5 MOhm. If it isn´t, replace C615 and C674
(both are class A). If that didn´t make it, replace D 600 (class B).
VLCD: If the value is incorrect, measure VDIG at N702:5, it should be 3,2 volt.
Measure the resistance between the pad and V611:1, it should be 0 Ohm, otherwise
is there a foil damage and the phone has to be discarded. Check the solderings on
D600:95 and D600:96. Measure the voltages on V611 pin 1=-2,7 V, pin 2=-1,6 V
and pin 3=-2,5 V. Do the same on V608 pin 1=-1,6 V, pin 2=0 V and pin 3=-1,0 V.
If any of the voltages are incorrect, replace the diode (or both) and try again. If the
fault still remains, measure the resistance of C632, C634 and C636, they should be
larger than 2,5 MOhm. Measure the resistance of C631 and C633, they should be
larger than 100 kOhm. Measure the resistance of C824, it should be larger than 25
kOhm. If any of the capacitors are faulty, replace it (they are all class A).Measure
also the resistance of R616 and R639 (100 kOhm), R807 (82 kOhm) and R808 (33
kOhm). If anyone is incorrect, replace it (they are all class A).If the fault still
remains, replace D600 (class B).
I2CDAT: If the value is incorrect, measure the resistance between the pad and
D600:3, it should be 10 kOhm. Is it larger, then measure the resistance of R614 (10
kOhm). If R614 is faulty, replace it (class A), is R614 correct then there is a foil
damage and the phone has to be discarded. Measure VDIG on R619 (2,2 kOhm,
class A), if it is lower than 3,2 volt, proceed to chapter 3 ("Doesn´t start"-fault). If
the things above are correct, replace D600 (class B).
If the fault still remains, send the phone to the next repair level.
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