Acer RA19WAANU 5.3Checking the back light unit, 22

5.Troubleshooting (continued)

5.3Checking the back light unit

Is+22V supplied to inverter PWB ? (by the

powerboard)

FailurePoint

1)Power board of Inverter part failure.

Checkthe BKLT_EN signal of the DC input

P301pin 1 at TTL high level.

FailurePoint

1)printed wire broke between P301 pin1,

R303and I305 pin 88.

2)I305 is failure.

Checkthe BKLT_ADJ signal of the input

P301pin3 from I305 pin86 is a PWM

signal.

FailurePoint

1)printed wire broke between P301 pin3,

R304,R357and I305 pin11.

2)Q302 is failure.

FailurePoint

1)Back light unit of LCD module is failure.

2)Inverter Cable disconnect

Go to cover page

ACERX193HQ

Contents

Main Model ID:RA19WAANU Service Manual DBG DPBU IIDBG DPBU II Service ACER ACER_LCD_X193HQ_SM080904V1 Page Page . Page PresetTiming Chart . Page 2.1 MAIN OSD MENU Outline: ACERX193HQ 8 The description for control function: 2OSD Menu Page Page Page S4 S5 S2 S3 S1 S11 S10 S6 S12 S8 S7 Page S6 S5 S7 S3 S4 Page Page S20 S21 S22 S23 Page 5.2 Nothing displays on the screen (Screen is black and colour of LED is blue.) 20 5.2 Nothing displays on the screen (Screen is black and colour of LED is blue)continued 21 5.3Checking the back light unit 22 5.4 Abnormalscreen for VGA 23 5.5 Abnormalscreen (For the DVI) 24 5.6Abnormal OSM display adjust problem 25 5.7Abnormal plug and play operation for VGA 26 5.8 Abnormalplug and play operation (For the DVI) 27 28 5.Troubleshooting (continued) 5.9.2Checking the control circuit of vertical sync pluse 5.10Checking the resolution change IC movement 29 5.11Checking the DC/DC converter circuit 30 5.Troubleshooting (continued) Page Page cedid Page LCD Flat Panel Interface Board Interface Board Audio line input Video Signal input DDC& Function key input