Acer LCD-S243HL service manual Backlight can’t be turned on

2. Backlight can’t be turned on

No raster?

Yes

LED orange?

Yes

Backlight can’t be turned on.

Yes

Is there 19V

No

voltage on pin23 of IC501,IC503

Yes
Is there high-level voltage	No
on pin1of IC501,IC503?

Yes

Are CN511 and CN512 connected rightly?

Yes

No

Is Pin24 of IC501,IC503(VREF) 5V?

Yes

No

Is ok L501,L502?

Yes

Check adapter

Yes

Is R501 OK?

No

No

Is IC501,IC503 ok?

No

Check I/F board

R501open

Connecting the output connector again

IC501,IC503 fail

L501,L502 fail

Check feedback circuit

END