Trouble Shooting
Page 21
NEC-FA150ATUA
14.4 Check the USB IC
Is 5V supplied to I201 pin 1 ?
Proceed section 14.5 " Check the power supply ".
Does it have the High level
(More than 4.75V ) from I201
pin 9,10,12
Proceed section 14.5 " Check the power supply ".
Does X201 oscillate (6 MHz) ?
Does the output of X201 satisfy a threshold level
( High:more than 4.75V,Low:less than 0.8V) ?
Failure point
I201 failure
Failure point
X201 failure
Isn't I201 pin 15 fixed on the
High level ( more than 2.0V ) ?
and isn't pin14 fixed on the
Low level ( less than 0.8v ) ?
Failure point
Faulty operation of the host PC.
Does it have the High Level ( more than
4.75V ) from I201 Pin 9.
Does R234 open ?
Failure point
R234 failure
Does Q205 short ?
Failure point
Q205 failure
Does Q201 short ?
Failure point
Q201 failure
Failure point
Faulty operation of the over current protection function.
Failure point
I201 failure
NG
NG
NG
NG
NG
OK
NG
OK
NG
OK
NG
NG
OK