HP Envy 15 does not turn on, only the LED on the PC connector is on!!!

[Leone22]

Hello community. I need your help to resolve the problem with my HP envy 15 notebook mod.15-k111nl. The problem is the following: inserting de connector of the notebook, the LED on the connector lights on but if I pressed the power button it doesn't happen Nothing.
I did some tests to verify where the fault could be and I noticed there are 3v but the 5v does not arrive.Furthermore I have a series of mosfets that seem to be in short circuit but desoldering them and testing them on the bench they are good. These are the signals that I found:
PL8:3,117v----PL9:0v---PL12-----PL13:0---PL16:0v---PL20:0v---PL16:0v----PL13:0v-- -
PL12:0v----PL9:0v---PL8:3,117v the above mentioned mosfets, that once tested resulted fine are the following:PQ23,PQ24,PQ25,PQ26.Find attached the electrical diagram and boardview of the notebook,
hoping that some guru can give me a hand in solving the problem .
Sorry for my rough english.
Thank you and best regards.

[MOD EDIT] Link to schematic -> https://www.badcaps.net/forum/troubl...b6c0-schematic

[mcplslg123]

Presence of light on dc jack is almost a sure sign of presence of 3V LDO. On many platforms 5V will come only after switching the MB. Since it doesnt turns on,you need to check and take steps:
01.Visual inspection for corroded elements
02.Flash known good bios
03.RTC circuit-presence of RTCRST#/SRTCRST# with 3 v cmos cell inserted,No power attached)
04.Basic requirements of SIO and see if RSMRST# is present or not.

[Leone22]

Thanks for the reply, I checked the various points on the card and found these values:

01:No visually damaged components
02:Tried rewriting the bios
03:RTCRST#= 2,746 v
SRTCRST#= 2,744 v
04:RSMRST#= 0 v
These are the values found, is the situation serious?

[mon2]

RSMRST#= 0 v

means this line is stuck in reset mode since this is an active low signal. It should be ~3v3 under normal conditions.

[mcplslg123]

Without RSMRST# present,mb wont switch at all. Time to check basic requirements of SIO,flash bios. What is the resistance to GND on RSMRST# pin?

[Leone22]

Hi, the RSMRST# resistor is 10k, I checked the voltages on the SUPER I/O and I realized that the 3v on pin 11 is missing.
I checked the voltages on IC PU11 and on the PC204 capacitor I have no voltage.....Short circuit on the 3.3v line or problems on ic PU11?

Thank you and good day.

[mcplslg123]

You cant expect voltage on PC204 in off condition. The votage there will appear only after switching and when EN1 pin has S5_ON from SIO. So in off condition,its ok to have only 3V LDO and nothing on coil.

I didnt asked for RSMRST# resistor. Thats a 10K pullup resistor. Measure resistance to GND on RSMRST# pin of SIO(black probe to GND,red probe on RSMRST# pin). Should be 10K or higher resistance.

[Leone22]

Sorry I didn't understand, I measured the resistance is 10k on the pin RSMRST# of SIO

[Leone22]

Can we try to do some tests for study purposes too or will I take it straight to the bin?

[mon2]

The resistance to ground on RSMRST# of 10k is correct due to the pull down (not pull up) R578 on this line. The question remains as to why this line is not proceeding to be a logic high to allow the board to boot. If this line remains at a logic low = 0 volts, the board is stuck in reset mode.

[Leone22]

What are the elements that could bring the line to 1? Any advice on what I could check or do?
Thank you

[mon2]

Trace the same label in the schematics. Whomever is driving this signal is responsible to make the line go high = logic ‘1’.