Sharp 902SH Service Manual page 42

902SH
(From page 2-33)
B
Does Error occur when the command VERS =
1 is entered? (*1)
NO
Use the wire method for measurement.
In the test mode, can synchronisation be estab-
lished with a simulator, etc.? (ANT terminal
input: -90 dBm)
Use the PUCA command. (*2)
NO
In mandatory reception mode (*3), is MCLK
output sent correctly?
YES
In mandatory reception mode (*3), is the RSSI
value normal?
YES
IC1400 or PWB is defective.
*1: The command input procedure will be described later.
*2: Check both "Yes" and "No" items when the PUCA command is not available due to the lack of a simulator (such as MT8820A made by Anritsu)
or other necessary devices.
*3: The command input procedure will be described later.
[Transmission system]
C
Use the PUCA command. (*2)
Are the appropriate signals for SP001, SP002,
SP003, and SP004 displayed on an oscillo-
scope?
YES
Is the transmission frequency correct?
YES
Is the transmission waveform normal?
(At maximum output, ACLR ± 5 MHz is –34 dBc
or less, occupied bandwidth is 4.3 MHz or less,
and modulation accuracy is 12% or less.)
YES
Is the output level is correct?
(21 to 25 dBm, at maximum output)
YES
The aerial circuit and parts are defective.
CONFIDENTIAL
The file system or SRAM is defective.
YES
YES
C
VCXO circuit or IC400 is defective.
NO
Are the appropriate signals for SP015, SP016,
NO
SP017, and SP018 displayed on an oscillo-
scope?
IC1400 or PWB is defective.
IC1400 is defective.
NO
Is the voltage approx. 1 V on both ends of
NO
C710?
IC700 is defective.
NO
At maximum output, is the voltage on IC630 pin
NO
1 acceptable (approx. 2.6 V)?
At maximum output, is the voltage 3 V or more
on both ends of C627?
FL001 and IC700 or PWB are defective.
2 – 34
NO
YES
YES
NO
NO
YES
NO
YES
FL001 and IC400 or
PWB are defective.
IC400 is defective.
IC630 or IC1200 is
defective.
IC630 or IC620 is
defective.