Trouble Shooting Guide, Advanced
4/00021-3/FEA 209 544/25 C
Ericsson Mobile Communications AB
49(78)
Fig. 13.4
If all the signals look correct, the fault most certainly is due to the power amplifier.
Replace the power amplifier and perform a new radio calibration.
If the radio calibration failed, the fault can be due to noise in one of the feed voltages VRAD
and VVCO.
Noise can be due to e.g. ageing filter capacitors (usually the electrolytes) or deteriorated
performance in the voltage regulators of the radio.
Noise can also come from the PLL-circuit and components around it.
If some signal is incorrect the fault is probably due to R512 – R515 or C520/C522.
If all signals are incorrect he fault is probably due to D600.
To Next Page
Loading...
