Acer X173 Service Manual page 36

3. Panel Power Circuit
Check CN601 PIN 23 should have
response from 0V to 5V When we
switch the power switch from on to off
Replace panel
4. Keypad Board
OSD is unstable or not working
Is Keypad board connecting normally?
Is Button Switch normally?
Is Keypad board normally?
Check main board
OK
OK
OK
OK
Check the PPWR panel power relative circuit Q601, Q602
In normal operation, when LED =green, R601 low level,
NG
If PPWR no-response when the power switch
Turn on and turn off, replace the U401- RTD2120L
NG
NG
NG
36
Connect Keypad Board
Replace Button Switch
Replace Keypad Board