Trouble Shooting Flow Chart; No Power - ViewSonic vp231wb Service Manual

6. Trouble Shooting Flow Chart

6.1

No power.

Yes
Check that C281 are 24V
Yes
Check that C262 positive is at 5V.
Yes
Check:
1. IC255 is O/P 3.3V.
2. IC253 is O/P 1.8V.
3. IC256 is O/P 2.5V.
4. IC252 is O/P 3.3V.
ViewSonic Corporation
Check that CN251 pin1, are approximately 24V
No
Failure point
FB251, FB251 failure
No
Failure point
D251, IC251, L251, Q255 failure
No
IC255, IC253, IC252, IC256
33
Failure point
1. Adaptor failure.
2. Disconnected between CN251 and Adaptor.
Failure point
Confidential - Do Not Copy
No
VP231wb