Acer E5-573TG DA0ZRTMB6D0 REV: D , No power

Post by **suryajaved** » Sun Oct 01, 2017 1:01 pm

Tips N Tricks :- 9
Laptop model :- ACER E5-573TG
PCB Number :- DA0ZRTMB6D0 REV: D
Problem Reported :- No power,
Observation:- Power On System After 3/4 time power Trigger
ACIN Not Present On pin72 of EC
Step:-1
Power on trigger was working, because PSU unit show some Amps consumption after power button press , but board not power up Completely, as useule in practice try to trigger 3-4 time and result was board power on Completely, now try to connect external keyboard to check that any activity on USB port is available or not , yes after pressing Num lock & Caps lock key led indicator was working accordingly, that indication of USB keyboard clear a stage that board have data processing and CPU acknowledge interrupt request by keyboard,
Step:-2
Trun Off and On PSU Power again and try to trigger, again same no power on with single trigger, Now start checking step by step supply's with Continues triggering all supply's are generated but trip , so decide step by step section checking first try to check charging section with battery , when plug battery and trun on PSU , PSU Amps consumption is 0 and first mosfet stop passing Voltage,
so start's checking charging chip requirements,
*Vcc = 17.5 v, Acdet=2.2v
Acok#=3.3v*
Complete parameters are wrong according to circuit, Due to ACOK# high PQ18 Active and get ACIN low so EC Not Detect ACIN on pin 72
Question

why ( PD3) Cross 19.5v to 17.5 v, trun of power remove battery and check Impedance of PD3 output line all are found Ok,
Now Big suspect is PD3 replace PD3 and bingo now PD3 output line voltage =18.9 , Acdet=2.4
Acok# = 0 After ACOK# get Low & ACIN been high 3.3v now set is working ok
All requirements of Charging Chip & EC chip is full fill now ,
Job done