HP ENVY 15 no power

[nassih]

hello everyone
its my second thread about this laptop
I will wish that someone can inform me of these voltage values:
PU12: pin1=1.6v pin7=8.6v(5vpcu).you can look in schematic
you can take a look at the schematic above

[emestee]

Re: HP ENVY 15 no power

1.6v is too low. The chip will not start switching. Check everything to the left of the EN signal.

There should not be 8.6V on the LDO output. Unfortunately there's no datasheet for this specific chip. The LDO output is used for the battery/adapter LEDs in the charger circuit, as well as for the ODT circuit on sheet 13.

My first guess would be the IC is damaged, but since this is exotic, you would want to rule out other sources first.

[nassih]

Re: HP ENVY 15 no power

indeed LDO should have a value of 5v because in the other side pu11 LDO is 3v and EN=0v

[nassih]

Re: HP ENVY 15 no power

PU12 is replaced too

[nassih]

Re: HP ENVY 15 no power

I noticed that before I replaced the pu11 SY8208b with SY8208C incorrectly i think

[nassih]

Re: HP ENVY 15 no power

SY8208b is 3 regulator, SY8208C is 5v regulator

[emestee]

Re: HP ENVY 15 no power

SY8208b is 3 regulator, SY8208C is 5v regulator

If PU12 is pulled out, what would be the voltage on the enable signal?

[nassih]

Re: HP ENVY 15 no power

If PU12 is pulled out, what would be the voltage on the enable signal?

PU12 pulled out EN pin is 0v
PU11 EN pin is 0v too

[emestee]

Re: HP ENVY 15 no power

PU12 pulled out EN pin is 0v
PU11 EN pin is 0v too

Check with an oscilloscope if possible.

[nassih]

Re: HP ENVY 15 no power

on other motherboard same DC/DC +3VS5/+5VS5 PU11 & PU12 pin1 EN is 0V,LDO is coming when power button is pressed 3V,5V on coil PL21 & PL20

[nassih]

Re: HP ENVY 15 no power

Check with an oscilloscope if possible.

is not available in my workshop

[stingerchamp]

Re: HP ENVY 15 no power

If you look at pu11 3vpcu there is a voltage divider attached to pin 7 ,what is voltage on pin7 and there is a npn transistor controlling sy8208cen
what is voltage on pin 1 ,2,3

Pu12 enable has s5_on signal is generated or not

[nassih]

Re: HP ENVY 15 no power

I will inform you when I will be at my workstore
tanks

[nassih]

Re: HP ENVY 15 no power

If you look at pu11 3vpcu there is a voltage divider attached to pin 7 ,what is voltage on pin7 and there is a npn transistor controlling sy8208cen
what is voltage on pin 1 ,2,3

Pu12 enable has s5_on signal is generated or not

PU11 pin7 is 4.8v i thik

[stingerchamp]

Re: HP ENVY 15 no power

Confirm it please

Voltage at r228 10 kilo ohm resistor on both ends as it is s5_on signal to generate enable signal for ic 3volt

and is npn transistor available at motherboard check schematic page sy8208c pq40

[stingerchamp]

Re: HP ENVY 15 no power

PU11 pin7 is 4.8v i thik

If vin 19v then at pin 7 of pu11 we must have 4.391volts

[nassih]

Re: HP ENVY 15 no power

hi im sorry for the delay
yes u are ok for PU11 pin7 its 4.374V

[nassih]

Re: HP ENVY 15 no power

R228 i have 3.2v in on side without pressing power button and 0.089v in other side pin 100 of U11 ITE. but 3.3V is coming when i press power button

[nassih]

Re: HP ENVY 15 no power

PS :all voltages coming when power button pressed coming and disappear immediately

[stingerchamp]

Re: HP ENVY 15 no power

Is pq40 available?

If s5_on is coming at pu12 pin it means pu12 ready to generate voltage at coil

Do you get voltage at coil after power button pl20 coil

Also mentioned check pq40 pin 1,2,3 its npn so need high voltage at gate which will ground sy8208c enable