acer 5742g power on 1secand

[ddhlawi]

hi
I have acer acer 5742g power on 1secand
When you press the power button, it draws about 40 mA
3v is OK
5v is OK
run power 3v 5v .1v is OK
slp s3 slp s4 slp s5 rsmrst is OK
bios is flash
no short
change cpu
NOT. After I removed the main BIOS chip and tested the device, it worked without data

[mcplslg123]

Re: acer 5742g power on 1secand

What is the mb code?? Check 3V/5V/1.5V dc-dc transfer(From ALW to VS) happening or not.

[ddhlawi]

Re: acer 5742g power on 1secand

What is the mb code?? Check 3V/5V/1.5V dc-dc transfer(From ALW to VS) happening or not.

yes is ok

[ddhlawi]

Re: acer 5742g power on 1secand

LA-5893P Rev:0.1

[Udemzy]

Re: acer 5742g power on 1secand

Impedance of all coils and voltage on all coils.

Once it powers on, check where the voltage stops on each coils

[ddhlawi]

acer 5742g no power

I have acer 5742g no power
the power button 18v
where is the problem

[mon2]

Re: acer 5742g power on 1secand

Start with checking the voltages on mosfets PQ51 & PQ52.

See attached.

[ddhlawi]

Re: acer 5742g power on 1secand

18 v

[mon2]

Re: acer 5742g power on 1secand

Post the voltages on each pin and each mosfet.

Source pins will be 1-2-3 ; pick one
Gate pin will be 4
Drain pins will be 5-6-7-8 ; pick one

[mcplslg123]

Re: acer 5742g power on 1secand

If you have 18V at switch, check 51ON# circuit.

[ddhlawi]

Re: acer 5742g power on 1secand

source pin is 19v gate 8v drain 19v

[mon2]

Re: acer 5742g power on 1secand

Same readings for both mosfets?

Remove all power. Meter in resistance mode

Check the resistance of each of these mosfets:

Source and drain
Source and gate
Gate and drain

[ddhlawi]

Re: acer 5742g power on 1secand

ec_on 0v

[usyusy]

Re: acer 5742g power on 1secand

ec_on 0v

flash clean and tested bios and check sio requirements