
PAMS Technical Documentation
Troubleshooting
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For the spectrum analyzer measurements in the following chart use the 500 ohm passive probe. Since
the signal measured is bursted it is advised to set the analyzer to maxhold.
Vpctrl GSM 900 @ power level 5
TXC signal @ power level 5
Measure TX
power on "ANT"
Power > 30.5 dBm
in 50 ohm.
Measure TX
power on "Pout".
Power ~ 8 dBm in
500 ohm
Measure TX
power on "Pin".
Power ~ -25 dBm
in 500 ohm
No
Measure TX
power unbal T504
Power ~ -30 dBm
in 500 ohm
With Osc check:
VTX = 2.7V +
discretes around
T504
Check POGO
pins, C593, L510
Yes
Measure TX
power on
GSM_Tx. Power ~
8 dBm in 500 ohm
With Osc on
RXTX switch
check: Vc1 = 0V,
Vc2 = 2.7V
Yes
Check L515
(Coupler)
Check RXTX
switch
Yes
Check Hagar +
Serial bus
With Osc on PA check:
Vpctrl GSM900. Vpctrl
~ 1.7Vpp (see figure ?)
Yes
Check PA N502
Yes
With osc on TX
buffer check:
TXBUF = 2.7V
No
No
Yes
No
Measure TX
power "TX buffer
input"
No
No
No
Yes
Check V601,
V602 + discretes
around
Yes
No
Check Z503
Yes
No
With Osc check
TXC (see figure
below)
With Osc check
"Vpctrl" ~ "TXC"?
Yes
No
Check V503 +
discretes around
No
No