Acer4752 Power On Issue

[dspok]

Hello,

I have a issue with this Acer 4752 laptop and in many other model I faced similar issue.

Machine voltages OK, charging OK, 3/5V Ok but won't turn on. If I remove RTC Battery machine turns on itself and display comes out.

No short or leakage in RTC section, SIO changed, BIOS reprogrammed, Processor changed.

Is PCH faulty? or something I'm missing please let me know.

Diagram here.. https://www.badcaps.net/forum/attach...5&d=1392865123

[ktmmotocross]

Re: Acer4752 Power On Issue

did u get all rsmrst , pwrok and pwrbtn signals ?

[mcplslg123]

Re: Acer4752 Power On Issue

I'm facing same issue with HP15 La-A994p mb. Everything seems to be ok as per schematics. Mb works fine with cmos battery for 10-15 days and then switches and instant off, without any display. Unplug cmos battery again starts working with display. Repeats same issue after 10-15 days. Frustated

[bachir2004]

Re: Acer4752 Power On Issue

hello,

i have a issue with this acer 4752 laptop and in many other model i faced similar issue.

Machine voltages ok, charging ok, 3/5v ok but won't turn on. If i remove rtc battery machine turns on itself and display comes out.

No short or leakage in rtc section, sio changed, bios reprogrammed, processor changed.

Is pch faulty? Or something i'm missing please let me know.

Diagram here.. https://www.badcaps.net/forum/attach...5&d=1392865123

last time i had this problem,i changed the crystal near pch.i do not remmember which model.but i could switch the mobo on by power button with no display but would not turn off untill unplugging charger.

[dspok]

Re: Acer4752 Power On Issue

@ktmmotocross
Yes all rsmrst , pwrok and pwrbtn are ok. I found Q1901 pin 2 and 3 = 3.3v but no voltage at pin 5 and 6. R1916 and R1909 are ok.

Laptop still turns on without RTC battery, but doesn't turn off.