Lenovo i909 Manual de mantenimiento - Página 24

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I908 Mobile Phone Maintenance Manual

Problem 3:

Problem: After several times of calibration, the output power is still higher than normal. And

then PA is damaged.

Cause of the Problem: PA and chips of VAPC input assemblies are out of position. PA is

damaged.

Solution:

4.3 Testing of the Unit/Problems during Repair

Problem： The switch spectrums and ramp masks of both GSM and DCS bands exceed the

limits.

Cause of the Problem: If R2103 (10K Ohm), R2104 (18K Ohm) or the capacitor C2105 (220pF)

on the V_ ramp signal cable of the PA are not soldered properly or damaged, this will cause

the frequency and spectrum to exceed norms.

Solution:

After several times of

calibration, the output

Is the voltage of PA (U2102) at Pin6 far

higher than 1.4V?

Are the upper parts of

and

C2105

PA may be damaged. Replace

C2105, R2104 and PA (U2104). Then

Switch

and Ramp Mask

Does the voltage of PA (U2102) at Pin6 falls

within the normal range (less than 1.8V)?

Check C2105 and R2104

(critical point) for possible

Replace elements with

pseudo soldering.

LENOVO

Replace

R2104

(U2108)

Spectrum

Page 24

Replace

(U2102)

and

repeat

and