Samsung NP350V5C not power on (main La-8861P REv 2.0 QCLA4)

Good morning friends.
I find myself fixing this samsung model NP350V5C notebook. Pressing the power button remains off, no LEDs. it does not rotate the fan.
Check voltage and signal:
+b present
+3VaLWP present
+55VALWP present
ACOK PU200 present (3.30V)

*** kbc ****
+3VL OK
SYSON 0V (IN OFF AND AFTER PRESS POWER BUTTON STAY 0V)
SUSP 0V (IN OFF AND AFTER PRESS POWER BUTTON STAY 0V)
ON/OFFBTN# 3,30V AND DROP TO 0V WHEN I PRESS POWER BUTTON
I did some tests, I reprogrammed the two bios uh4 and uh3 but it does not turn on. I replaced the kbc without reprogramming it because i'm waiting for the rt809f to arrive.
What can I check?
Thank's

Measure voltages on pin 6, 9, 14, 37, 100, 127 of KBC.
Measure voltages on KBC pin 114 in the following cases:
at power off
with power on pressed
al power on.

robgerr ha scritto:What can I check?

- check UCL1 and YCL1 (resonance).
Or desolder GCLK and CCL7 and check again.

kbc measure:
pin 6 0v
pin 9 3,27v
pin 14 0v
pin 37 3,27v
pin 100 0v
pin 114 3,27 v power off, when press power button drop to 0v, after release power button come up to 3,27v

oscillator group UCL1
pin 1 oscillation ok
pin 5 oscillation not present
pin 6 oscillation not present
pin 9 oscillation ok
pin 16 oscillation ok

YCL1 oscillation ok

robgerr ha scritto:I replaced the kbc without reprogramming it because i'm waiting for the rt809f to arrive.

Is your measurements with old KBC chip? If yes, measure the following voltages.

Measure voltage to ground on pin 124 of KBC chip.

Measure voltage to ground on pin 106 of KBC chip in the following cases:
a) Power button released
b) Power button pressed

Measure voltage to ground on pin 100 of KBC chip in the following cases:
a) Before pressing on the power button
b) After pressing on the power button

UCL1 works ok.

Replace the bios and remember to save the old one.
Reflow PCH.

No measurements with new kbc but i remeber the syson signal not work wih old kbc. I ordered rt809f for reprogramming kbc but i semi-repaired another mainboard( same model mainboard)replacing kbc but not remprogrammed. that mainboard power on but backlight not work, missed backlight enabler from kbc but bypasses with another 3,3v signal (connetc backlight signal wih other 3,3v signal and mainboard power on, display perfect image and load operating system but keyboard not work propelly and fun spin full, but machine load ok.on this motherboard I thought about replacing the kbc without reprogramming it and doing it but I think the problem is anything else, maybe pch arrived at this point. To see if in the power on scale, first comes the syson command from the kbc or first comes the signal from the pch?

robgerr ha scritto:To see if in the power on scale, first comes the syson command from the kbc or first comes the signal from the pch?

The start-up process is the following:
In standby runs only KBC controller (and RTC part of PCH), another parts of PCH are in reset mode.
When the power button is pressed KBC cuts off the reset of PCH, and send it enable signal. PCH wake up and send power on signals to the KBC, which turns ON the motherboard.

matic ha scritto:Measure voltage to ground on pin 124 of KBC chip.

Measure voltage to ground on pin 106 of KBC chip in the following cases:
a) Power button released
b) Power button pressed

Measure voltage to ground on pin 100 of KBC chip in the following cases:
a) Before pressing on the power button
b) After pressing on the power button

kbc (new, no programmed):
pin 124 1,68v
pin 106 power button release 0v,power button pressed 0v
pin 100 power button release 0v,power button pressed 0v
Reflow pch but same problem,no power on

Program the KBC chip, then repeat the measurements.

Ok, i'm wait rt809f, program kbc and repeat measurement

Reprogrammed kbc and computer power on perfect. Very Thank's friend's