Ericsson SH 888 Trouble-Shooting Instruction page 15

Measure the VDIG and VDSP voltages (~3.2V, fig. 3.1).
• If any of the voltages are too low, measure the resistance from it to ground
(VDIG - >500 ohms, VDSP - >25 kohms).
* If the resistance is correct, replace the corresponding regulator (VDIG -
N702, VDSP - N701, both of class A, fig. 3.1).
* If it's too low, send the phone to the next level.
• If any of the voltages are too high, replace the corresponding circuit.
Check the power reset (PWRRST) voltage at C710 (fig. 3.1, >3V).
• If it's less, measure the resistance of R704 (~0 ohms, class A, fig. 3.1) and R725
(~100 kohms, class A, fig. 3.1).
* If they're correct, replace C710 at first and if that doesn't help, N703 (both
class A, fig. 3.1) .
Measure the VRAD, VVCO and VRPAD voltages (~3.8V, fig. 3.1).
• If any of the voltages are incorrect, measure the resistance from it to ground (>50
kohms).
* If the resistance is correct, replace the corresponding transistor (see fig. 3.1,
all of class A).
* If the resistance 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 D610 (class A) at first and then D600 (class B). Try pro-
gramming the phone in between.
3.4.3 Consumes more than 200mA.
Open the phone and check for liquid damages.
Make sure the system connector pads aren't damaged or burnt.
Mount the board in the fixture. Start it up and keep it running by keeping DCIO
high.
Check the current consumption again.
• If it's less than 200mA, check the back cover gasket.
* If it's ok, replace the display and the elastomer and try again.
Check the resistance from VBATT to ground (>1 Mohms)
• If it's less, send the phone to the next level.
Check the VDIG and VDSP voltages (~3.2V, fig. 3.1).
• If any of the resistances are too low, measure the resistance from it to ground
(VDIG - >500 ohms, VDSP - >25 kohms).
4/00021-2/FEA 209 544/3.D
SH888, S868, Standare Electrical Repair
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