Power unit operation check (SHPWR0000137)
Are the power cord and extension cable in
the unit properly connected?
Connect the power cord and extension cable
properly, and turn on the power again.
No
Yes
Is F1 normal ?
Are both components (VR2 and VR3) Low
impedance when checking their resistance
values?
No
Yes
Is F2 normal ?
Is it low impedance when checking the
C5&C8 Resistance values?
No
Replace F1
Yes
Yes
Is a 390~450V voltage on the C8?
Replace F2
Yes
Is it not enough 390Vdc?
No
Yes
Check PFC stage, including D5,L2,Q2,Q3
and IC1
Yes
Is there power down signal (3~3.4V) on the
PIN 3 of CX400 between the PIN 2 of
CX200?
No
Is there 3.3V output on the C94
Yes
Does the PSU_STBY Voltage from system?
Yes
To check Q8 and PC5.The
Q8 and PC5 was conducted
when the AC voltage
applied to PSU.
Continued on next page.
No
Replace
PSU.
LC-32WD1E/S/RU, LC-37WD1E/S/RU, LC-42WD1E/S/RU, and LC-32/37/42WT1E
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