7-10
7.11 Copy Quality is Too Bright
Yes
Check if D9, D10
connected inversely
No
Solder anew
Check U3-7 white level >
3.3V
Yes
Check U1-67, 71
No
Check U3
7.12 Failed to Transmit Successfully
Check U24-46, 22
normal
Yes
No
Power supply circuit
defective
Check the
oscillctor
circuit
Check if U24-67 high
Check if U24--54 active
No
Power on reset
circuit defective
Yes
No
Modem defectiv
Yes
Check the solder state of
U1-121 is good
Yes
Note 1:
Check if there is signal in
U24-45 handshaking
Receiving circuit
defective
No
Yes
Check U22-1 signal
Receiving circuit
defective
No
Yes
NCU circuit defective
Note 1:
1. If Tx level is around -10dB.
2. The waveform is sine wave (measure with
scope 1V, 1ms); followed by modulated
waveform whose amplitude is below Vpp3.5V.
Resolder U1
No
Summary of Contents for TF-300P
Page 1: ...I TF 300P Field Service Manual Ver 02 July 8 1999 TTIC...
Page 12: ...1 7 1 3 General Appearance 1 3 1 Appearance 1 3 2 Show the operation panel...
Page 84: ...7 23 Check the status of C24 C25 C26 R32 R34 L11 and L12 Check the Microphone inside handset...
Page 100: ...9 1 9 MECHENICAL DRAWING AND PARTS LIST...
Page 101: ...9 2...
Page 102: ...9 3...
Page 103: ...9 4...
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Page 116: ...10 1 10 CIRCUIT DRAWING...
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