Acer AL1916 AL1916v Service Guide - Page 35

3. Panel Power Circuit Check CN101 PIN 23-24 should have response from 0V to 5V When we switch the power switch from on to off OK Replace panel Check the PPWR panel power relative circuit,Q706, Q704 In normal operation, when LED =green, R725 NG Should =5 V, If PPWR no-response when the power switch Turn on and turn off, replace the U401-TSUM16AK 4. Keypad Board OSD is unstable or not working NG Is Keypad board connecting normally? OK NG Is Button Switch normally? OK NG Is Keypad board normally? OK Check main board 34 Connect Keypad Board Replace Button Switch Replace Keypad Board