Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

[flatline]

I see 19v in a few areas. None of the coils are shorted to ground. And I haven't detected any shorts in the obvious areas. There is no response when i press the power button. There is 0.00 Amps drawn from bench power supply at 19v power connector.

[flatline]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

Just want to add that I have a very basic understanding of these motherboards.

[Techtiger]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

Check PL20 PL21 +5VS5 +3VS3 , PU11 pin 5 PU12 pin7 LDO 3/5 output Voltage & your RTC 3.3V section

[flatline]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

PL20 and PL21 are both 0V

PU11 pin5 is 3.3V

PU12 pin7 is 5V

[flatline]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

voltages at U9 for RTC

pin2 is 0V
pin10 is 3.0V
pin14 is 2.8V
pin15 is 3.27V

[flatline]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

Regarding PL20, PL21. When power is initially applied to 19v connector, they both get a quick blip of voltage for a split second, then down to 0v, almost too fast for the multimeter to show. I was able to read 2.1v at the aluminum capacitor c747 as it slowly discharges. Also, pin 8 on bios chip shows this quick blip of voltage as well.

[flatline]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

I checked (pu1) (bq24738H)

pin10 looks low, but I don't know if it's supposed to be 1v when board is at idle, then 3v when board is powered on?

pin1,2,3,20= 19.5v
pin4= 25v
pin5= 3v
pin6= 2.6v
pin8,9= 3.3v
pin10= 1v
pin11,12,13,18,19= 2.8v
pin14= ground
pin15= 0v
pin16,17= 6v

[flatline]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

Okay, this one is interesting.

(pu10 APW8713QBI-TRG)

Pin1,2,3,4,5 = 0v
Pin6 =11.2v
Pin7 cycles from 0v to 300mv then repeats
Pin8 =19.5v
pin9 =19.5v
Pin10,11 =0v
Pin2,13,14,15 grnd
Pin16,17,18 =0v
Pin19 grnd
pin20 =0v
pin21 =0v
pin22 =19.5v
pin23 =300mv

[flatline]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

PL16 is showing 150ohm to ground

[flatline]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

pc182 seems to be open. It's a .1u cap

[Techtiger]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

PU11 pin 1 7 8 Voltage PL21 ohm ?
PU12 pin 1 5 8 Voltage PL20 ohm?

[Techtiger]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

Okay, this one is interesting.

(pu10 APW8713QBI-TRG)

Pin1,2,3,4,5 = 0v
Pin6 =11.2v
Pin7 cycles from 0v to 300mv then repeats
Pin8 =19.5v
pin9 =19.5v
Pin10,11 =0v
Pin2,13,14,15 grnd
Pin16,17,18 =0v
Pin19 grnd
pin20 =0v
pin21 =0v
pin22 =19.5v
pin23 =300mv

This IC if fine it Enables after S3/S4 signel

[Techtiger]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

PL16 is showing 150ohm to ground

150ohm with RAM or without ?

[flatline]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

Hi techtiger, PL16 is 150ohm with or without RAM.

PL21 3k ohm
PL20 70k ohm (takes a few seconds to settle fom 130K-70Kohm)

PU11 Pin1 7 8
0V 4.5V 19.5V


PU12 Pin1 7 8
0V 5V 19.5V

PL20,21 are 13ohm when I accidentally checked for ohms while power supply is still on board and supplying power. And of course, there is no voltage at PL20,21. But I guess that means there is a gate to ground?

[khaahk]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

Pressing power button brings NBSWON1# from 3V to low state?
After that IT8987 should bring DNBSWON# high and give a short low pulse to cpu.
Cpu should respond with susb# and susc# going high.

IT8987 might need to be reprogrammed.

[flatline]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

Hello khaahk,

NBSWON1# press button, 3v then 1.8v blip, then back to 3v

DNBSWON# press button, 40mv for about 1second.

susb# press button, nothing happens, 0v

susc# press button, nothing happens, 0v

[flatline]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

PU3 (NCP81101MNTXG)

PIN8 Rising and Falling Voltage. What's BST?

[flatline]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

PL14 is 110 ohms to ground.

[Techtiger]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

Now check PU11 SIO pin 100 14 119 97

[flatline]

Re: Dead no response. No lights at all. Got 3v at pwr button, But 0v at bios pin 1,8

U11 SIO IT8987

Pin14 3.25V EC_WRST
Pin97 3V ACIN
Pin100 16mV S5_ON
Pin119 0V RSMRST#