Samsung SMX-K40BN Service Manual page 20

Troubleshooting
4-12
USB doesn't work
Does USB CABLE work
normally?
Yes
USB_5V(CN202)
Comes out?
Yes
USB_DET(IC201 19pin)
Comes out?
Yes
Is USB
signal out
of CN202(DP, DM)
Yes
Does the
Clock of IC401 Work nor-
mally? X401= 12MHz
Yes
Does
IC401(NIKE)
Work normally?
Yes
Does it
work normally
After having Image
Upgrade?
Yes
Repair is done
No
Replace USB CABLE
No
Check CN202 5pin=5V
No
Check IC201 19pin(USB_nDET)
Refer to a pattern
image of Table 4-4
No
Check CN202
Refer to a pattern
image of Table 4-4
No
Check X401
Refer to a pattern
image of Table 4-4
No
Replace IC401 or Main B'd
No
Replace IC401 or Main B'd
Samsung Electronics