Acer MB243WABNS service manual Proceed to 5.3 Checking the backlight unit section

5. Troubleshooting (continued)

5.2 Nothing displays on the screen (Screen is black and colour of LED is blue.)

ACER G24 21

Go to cover page

Check if the backlight is

slightly lightened from upper

Proceed to “5.3 Checking the backlight unit” section

NG

corners (right/left) of LCD

panel

OK

Does RGB video

1. Change pattern of video signal outputs from

the PC host to optimum resolution.

signals output

NG

2. Reconnect the video cable.

from connected PC host?

3. Cross-test the other workable video cable.

OK

Failure Point

Check if OSM menu

Check if video signal cable

is displayed upon pressing the

NG

is connected properly between

NG

The cable is disconnected.

“MENU” key

LCD monitor and PC host

OK

Proceed to “5.4 Abnormal Screen” section.

OK

Check if 3.3V is

Failure Point

supplied from I301 pin2; 2.5V is

Check if the

supplied from I303, pin2, and

Voltage on I301, I303,

the 1.8V power is supplied from

NG

I320 pin3 is high DC

NG

1. Printed wire is broken between

I302 pin2.

level at 5V.

P301 pin1, pin2, pin3, pin4 and

I301, I303,

I320.

2. Check power board

OK

OK

Failure Point

Check all LVDS signal pins;

I301, I302, I303, or I320 is

damaged.

output from I314

OK

NG

Failure Point

Failure Point

Printed wire is broke or short

1. The cable is broke between

between P306, I314

P306 and LCD panel.

2. LCD panel is defected.