Asus GL552VW - nie uruchamia się

Cześć.
Laptop po rzekomym lekkim upadku (brak śladów na obudowie i matrycy).
Po podłączeniu zasilacza następuje autostart płyty, pobór prądu 37mA. Nie reaguje na włącznik. Zapala się led5602 (power led) oraz lekko żarzą led5604 i 5603 (caps lock i numlock).
Na chwilę obecną został przeprogramowany BIOS i KBC oraz podstawiony inny PCH - bez zmian.
Nie wykryłem żadnych zwarć, pod termowizją nic się nie grzeje.
Poniżej pomiary napięć i oporności cewek.

Proszę o pomoc w rozwiązaniu usterki.

Hello!

- Measure the voltages to ground on all pins of BIOS chip U2801.
- Measure the voltages to ground on pins 1, 2, 4 of chip U2401.
- Measure the voltage on capacitors C2002, C2003.
- Measure the voltages to ground on both pins of quartz X2202 with oscilloscope. If you don't have it, measure with a multimeter.
- Measure the voltages to ground 4, 12, 14, 18, 19, 21, 35, 57, 66, 67, 69, 70, 74, 82, 83, 85, 86, 96, 98, 99, 108, 109, 111, 127 of KBC chip.

- Measure the voltages to ground on pins 56, 110 of KBC chip in the following cases:
a) Power button released.
b) Power button pressed.

Thank you for your answer.

U2801:
1-3,37V
2-3,35V
3-3,36V
4-0V
5-0V
6-0V
7-3,35V
8-3,37V

U2401:
1-2,37V
2-0V
4-0V

C2002 - 3,05V
C2003 - 3,05V

X2202
1-345mV
2-320mV

U3001
4-2,24V
12-1,79V
14-3,26V
18-13mV
19-3,27V
21-3,29V
35-3,36V
57-3,36V
66-3,36V
67-3,32V
69-0V
70-3,34V
74-3,29V
82-3,27V
83-3,29V
85-3,29V
86-3,29V
96-3,27V
98-0V
99-0V
108-0V
109-3,26V
111-3,29V
127-3,29V

56 KBC pin:
-Power button released -3,29V
-Power button pressed - 3,29V

110 KBC pin:
-Power button released -3,26V
-Power button pressed - 0V

koper912 napisał(a):U2401:
1-2.37V

Is this measurement correct?

Set your multimeter to the diode test mode and measure the voltage drops to ground on pins 5, 6 of BIOS chip U2801.

matic napisał(a): koper912 napisał(a):
U2401:
1-2.37V

Is this measurement correct?

Yes, I have 2,37V on 1 and 5 pin U2401, because i have incorrect Voltage on rail +12V. I have only 4,1V on +12V rail.
On this rail I have Over Limit resistance to ground. Broken PD8700?

Voltage drop to ground on U2801:
5-1,75V
6-1,64V

Measure the resistances to ground on pins 3, 4 of transistors PQ8812, PQ8814.

If all resistances are high (at least 10kΩ), measure the voltage to ground on pin 19 of chip PU8700. Best with oscilloscope, if you don't have it, measure with a multimeter.

PQ8812:
3-0,99MR
4-Over Limit

PQ8814:
3-0,51MR
4-Over Limit

On 19 pin PU8700 I have 0V.

- Measure the voltages to ground on pins 3, 6, 7, 12, 13, 14, 20 of chip PU8700.
- Measure the voltages to ground on coils PL8700, PL8701.

PU8700:
3-3,29V
6-3,29V
7-3,27V
12-19,39V
13-5,11V
14-5,11V
20-3,29V

PL8700 - 5,11V
PL8701 - 3,37V

Replace the PU8700 (TPS51285A).

I replaced PU8700 and I still had 4.1V on +12V rail.
Then I replaced PD8700, apperead correct voltage on +12V rail.
Motherboard starting upo correctly and working very well.
Thank You Matic for Your help in resolve my problem.