DELL 3721-7960 LA-9102P - po zalaniu, brak reakcji

Witam

Płyta VAW11 LA-9102P rev 1.0(A00)
Po przyciśnięciu POWER - brak reakcji
Zalana w okolicy kości bios. Bios przeprogramowany wsadem z tego forum.

Napięcia na cewkach:
PL200 - 3,3v
PL201 - 5v
PL202 - 19,5v
PL300 - 0v
PL700 - 0v
PL701 - 0v
PL600 - 0v
PL100 - 0,47v

Brak napięcia na włączniku

Oczywiście w pierwszej kolejności płyta została wymyta, i przejrzana pod lupą - nie ma śladów korozji.

Proszę kolegów o pomoc

Hello!

Measure the resistance to ground on pin 114 of KBC chip.
Measure the voltages to ground on pins 8 and 17 of PU200.

matic napisał(a):Hello!

Measure the resistance to ground on pin 114 of KBC chip.
Measure the voltages to ground on pins 8 and 17 of PU200.

PIN 114 KBC - 99 KΩ

PIN 8 PU200 - 3,3v
PIN 17 - 5,11v

Measure the resistances to ground on all pins of diode DE1.
Measure the voltages to ground on both pins of resistor RE49.

matic napisał(a):Measure the voltage to ground on both pins of resistor RE49.

MATIC - can you let me know where i can find them?

igore napisał(a):

matic napisał(a):Measure the voltage to ground on both pins of resistor RE49.

MATIC - can you let me know where i can find them?

The BoardView is currently not available. Please post a clear picture of diode DE1 area. If I'm not mistaken it is located near the KBC chip.

Measure the resistances to ground on all pins of diode DE1.

Attachet photo.

25 MOhm on 2 pins od DE1- multimeter show for a sec then show OFF - probably out of scalle to measure this resistance - checked with 2 multimeters, and both show same.

Measure the voltages on all the pins of DE1.

Machine napisał(a):Measure the voltages on all the pins of DE1.

As on photo:

I think that the RE49 is the highlighted resistor (see the following picture). Check, if one pin of this resistor is connected to pin 2 of diode DE1 and another one to pin 8 of PU200. If so, it is RE49.



Diode DE1 pin count:


Measure the voltages to ground on both pins of RE49.

Edit:
According to your voltage measurements on diode DE1, there should be 3.3V on the power button.
Measure the resistance between pin 1 of diode DE1 and pin 3 of the power button connector JPWR.

matic napisał(a):I think that the RE49 is the highlighted resistor (see the following picture). Check, if one pin of this resistor is connected to pin 2 of diode DE1 and another one to pin 8 of PU200. If so, it is RE49.



Diode DE1 pin count:


Measure the voltages to ground on both pins of RE49.

Edit:
According to your voltage measurements on diode DE1, there should be 3.3V on the power button.
Measure the resistance between pin 1 of diode DE1 and pin 3 of the power button connector JPWR.

You are right - JPWR connector are faulty, after replacement, motherboard will turn ON, PWR diode light, but not show on screen. Checked one more time coils voltages after turn on, and no new voltages show, Only 3,3/5v , 0,47v and 19,5v

Measure the voltages on pins 6, 9, 14, 16, 32, 95, 100, 110, 116, 124, 127 of KBC.
Measure the voltages on pin 114 of the KBC in the following cases:
at the power off
with pressed power on
to the power on.

Machine napisał(a):Measure the voltages on pins 6, 9, 14, 16, 32, 95, 100, 110, 116, 124, 127 of KBC.
Measure the voltages on pin 114 of the KBC in the following cases:
at the power off
with pressed power on
to the power on.

here are measurments:

6 - 0v
9 - 3,3v
14- 0v
16 - 3,3v
32 - 3v
95 - 0v
100 - 0v
110 - 3,3
116 - 0v
124 - 0,3v
127 - 0v

114-
Power off - 3,3v
Pressed PWR BTN - 0,43v
Power on - 3,3v

Remeasure the voltage to ground on pin 124 of KBC chip.

Measure the voltages to ground on coils PL400, PL500, PL1100 (if it is present on the board), when the laptop is turned on.
Measure the voltage to ground on pin 1 of QC3, QZ1, QZ7, UZ1, when the laptop is turned on.

124 KBC - 1,7v

PL400 - 0v
PL500 - 0v
PL1100 - not have

PIN1
QZ1 - 0,37v
QZ7 - 0,7v
UZ1 - 0v
QC3 - 0v

Measure the voltages to ground on pins 6, 14, 95, 100, 116, 127 of KBC chip in the following cases:
a) Before pressing to the power button.
b) After pressing to the power button (laptop turned on).

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

KBC:

PIN6 a - 0v / b - 0v
14- 0/0
95 - 0/0
100 - 0/3,3
116 - 0/0v
127 - 0/0v

106
c - 0v / d - 0v

When motherboard is power ON - i have on this pin 1,88v

Reflash the KBC chip. Don't forget to save the old dump.

KBC dump is available on the forum: https://www.elvikom.pl/dell-inspiron-17r-3721-t34868.html#p152471

Communication with the PCH is lacking.
If the new bios does not solve, replace the KBC.

Machine napisał(a):Communication with the PCH is lacking.
If the new bios does not solve, replace the KBC.

Programmed bios from this forum, trying to programm KBC but svod get an error to erase chip: "Error blank check in page: 0 byte 1"
Svod read chip - but dump have onlu 128 KB

Chip really for replacement?