Lenovo G485 LA-8681P SUSP# is missing

[ruletero]

Hi everyone

I have this motherboard LA-8681P and it does'nt turn on.

I have BATT+, +5VALWP, +3VALWP and sometimes it turn on but almost always not.

When it turn on it hasn't video, have +1.5VP but nothing signal more and turn off 3 seconds next.

In accordance with the power secuence the next signal es SUSP# but it is missing, the EC doesn't release it

I already have programmed bios and there isn't a short in some coil, I think EC is bad.

Could someone help me please?

Thanks in advance

[piernov]

Re: Lenovo G485 LA-8681P SUSP# is missing

SUSP# comes up after SLP_S3#

[ruletero]

Re: Lenovo G485 LA-8681P SUSP# is missing

Yes but I have 1.5V activated by syson thus I must to have SLP_S3# in accordance with the power secuence or I'm in mistake?

Thank you

[piernov]

Re: Lenovo G485 LA-8681P SUSP# is missing

SYSON comes up after SLP_S5#.
SLP_S5# and SLP_S3# should come up at the same time when PCH wakes up from S5 state. Confirm it's the case.

[ruletero]

Re: Lenovo G485 LA-8681P SUSP# is missing

Sorry, I'm not explaining fine or l'm not unferstanding... I'm sure I have syson because I checked (3.2v) and it is the enable signal for 1.5v power supply.

Thus if I have SYSON then I have SLP_S5# and SLP_S3# too or that is my logic.

The problem is SUSP# is not released and then all the signals (including SYSON) goes down.

[Techtiger]

Re: Lenovo G485 LA-8681P SUSP# is missing

Check SIO SUSP# pin Resistance to GND , Discharge SIO take a wire 1point to GND other to all pins one by one with out any power remove RTC

[Techtiger]

Re: Lenovo G485 LA-8681P SUSP# is missing

Find out CLRP1SHORT PADS is getting 3.3V +RTCBATT find out Q63 & for any Short or leak

[Techtiger]

Re: Lenovo G485 LA-8681P SUSP# is missing

If above is not working go to Page 35 Put a jumper 3/5 ALW to 3/5VS FCH will heat UP press PWRBTW several times feed back

[piernov]

Re: Lenovo G485 LA-8681P SUSP# is missing

Sorry, I'm not explaining fine or l'm not unferstanding... I'm sure I have syson because I checked (3.2v) and it is the enable signal for 1.5v power supply.

Thus if I have SYSON then I have SLP_S5# and SLP_S3# too or that is my logic.

The problem is SUSP# is not released and then all the signals (including SYSON) goes down.

The laptop is not working. Anything can be wrong. You have to check all the signals that are involved.

[ruletero]

Re: Lenovo G485 LA-8681P SUSP# is missing

Check SIO SUSP# pin Resistance to GND , Discharge SIO take a wire 1point to GND other to all pins one by one with out any power remove RTC

Hi Techtiger

I did that you told me and saw the 116 pin in EC (SUSP#) has corrosion, sorry should have checked that before

I cleaned and resolded the pin and I have SUSP# and the motherboard turn on sometimes, then I did a little reflow to the PCH and now the mobo turn on always (or almost always)

I'm going to take it to reballing with a friend but for now this thread is finished.

Thank you all for your help!