Lenovo G50-80 Turns on and off within 4-5 seconds

[m1rc34]

Re: Lenovo G50-80 Turns on and off within 4-5 seconds

Has somebody solved this? I have the same issue

[ktmmotocross]

Re: Lenovo G50-80 Turns on and off within 4-5 seconds

check resistance and voltage on CPU

[qayyum786]

Re: Lenovo G50-80 Turns on and off within 4-5 seconds

ANSWER
I KNOW I AM TOO LATE TO REPLY
BUT THIS WILL HELP TO ANOTHER PEOPLE WHO HAS SAME ISSUE AND REPEATING SAME MISTAKE

Q25 gate should be active low
"SUSP#" SIGNAL WILL COME AND DEACTIVATE "SUSP" SIGNAL
It mean when ground will come on the gate Q25
Than only "20VSB" will release and activate +5VALW TO +5VS

[Radio Operator]

Re: Lenovo G50-80 Turns on and off within 4-5 seconds

it was a mosfet 4483A failure mine problem

[Solac03]

Re: Lenovo G50-80 Turns on and off within 4-5 seconds

ANSWER
I KNOW I AM TOO LATE TO REPLY
BUT THIS WILL HELP TO ANOTHER PEOPLE WHO HAS SAME ISSUE AND REPEATING SAME MISTAKE

Q25 gate should be active low
"SUSP#" SIGNAL WILL COME AND DEACTIVATE "SUSP" SIGNAL
It mean when ground will come on the gate Q25
Than only "20VSB" will release and activate +5VALW TO +5VS

hi sir what is the value of q25 ? i have the same issue and will try to change q25

[Solac03]

Re: Lenovo G50-80 Turns on and off within 4-5 seconds

ok i have checked q25, correct me if i am wrong. when there is power drain side of q25 should have 5V ? i have measured gate pin of q25 give intermitent 5v, i noticed that when the power led turns on the voltage drops and goes back when power led turns off. To switch on q23 pin 4 (gate) should have 5v, so that pin 123(drain) of q23 will have +5vs. i have tested my board and q23 does not have +5vs. my board keeps blinking power led when adapter is plugged in, even if not switched on. also fan seems to spin a bit and stops. i don't really know if q25 is broken i have tested drain and source using diode mode seems to be fine. where does the SUSP# singnal come from ? the diagram has q26 but my board does not have q26.

[Solac03]

Re: Lenovo G50-80 Turns on and off within 4-5 seconds

Up

[lordgeny]

Re: Lenovo G50-80 Turns on and off within 4-5 seconds

i have the same problem but if i try to turn on 3 4 times then it starts