ETS2228 Maintenance Manual
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Page 30, Total 43
Chapter 5 Troubleshooting
（
1
）
Troubleshooting Procedure of the Baseband
1
、
Power fault maintenance procedure
Figure 11 Power fault maintenance procedure
YES
YES
YES
YES
YES
NO
NO
power-on and startup
Check if Q301 is
good.
Chiefly check if CE
junction of Q301 is good
Check if
TL494(U302)
is good
Check if the voltage of foot 4 of
U302 is 5V.
Check if the voltage of
foot 4 of U302 is 1.25V.
Check if
R312(0.1ohm) is good
Check if D304 is good
End
NO
NO
NO
