Dell Studio 1555 MB: DA0FM8MB8E0 REV:E Brak reakcji

Witam,
Model: Dell Studio 1555
Płyta: DA0FM8MB8E0 REV:E
CPU: Intel T4300
KBC: IT8512E-JXA
BIOS : 25X16AVSIG

Laptop się nie włącza. Nie pali się żadna dioda. Laptop nie był zalany. Brak 3.3V_ALW.

Oporności na cewkach:

PL2 - OL
PL6 - 3,2 kOhm
PL7 - 73 kOhm
PL8 - 73 kOhm
PL3 - 18 Ohm
PL1 - 18 Ohm
PL4 - 37 Ohm
PL5 - 8 Ohm

Na PU5:
4 - 5,45V
6 - 19,6V
7 - 5V
25 - 0V
26 - 0V
27 - 0,5V

na PR156 - z obu stron 0,5V
na PR159 - z jednej strony 5V z drugiej 0,5V

Proszę o pomoc.

Hello!

Measure the voltages to ground on both pins of resistor PR154.

matic написав:Measure the voltages to ground on both pins of resistor PR154.

0,06V on both pins

Are you sure there is 5V on coil PL8?

matic написав:Are you sure there is 5V on coil PL8?

On PL8 - 0V

On PR159:
1 - 5V
2 - 0,5V

Remove the transistors Q6 and Q23 one by one from the board and check if anything changes.

matic написав:Remove the transistors Q6 and Q23 one by one from the board and check if anything changes.

The transistors removed.
The same situation like post 5.

Measure the resistance to ground on pin 2 of resistor PR159.

matic написав:Measure the resistance to ground on pin 2 of resistor PR159.

115 kOhm

Is the resistor PR159 (39kΩ) good?
If so, also remove the transistor PQ40 and diode D31 one by one from the board and check if anything changes.

matic написав:Is the resistor PR159 (39kΩ) good?

Yes, it is good. I removed rezistor for measurement. For my sure.

matic написав:If so, also remove the transistor PQ40 and diode D31 one by one from the board and check if anything changes.

Nothing changes. The same situation as before.

Is the resistor R154 present on your board?
If not, inject 3V from the laboratory power supply to the pin 2 of resistor PR159. What electrical current flows from the laboratory power supply in this case?

matic написав:Is the resistor R154 present on your board?

The board have rezistor PR154.

Should I remove it and inject power supply to the pin 2?

Bezel018 написав:The board have rezistor PR154.
Should I remove it and inject power supply to the pin 2?

First try to remove the resistor PR154 from the board and remeasure the voltage to ground on pin 2 of PR159.
If nothing changed, try to inject the voltage as suggested.

matic написав:First try to remove the resistor R154 from the board and remeasure the voltage to ground on pin 2 of PR159.
If nothing changed, try to inject the voltage as suggested.

On PR159 on pin 2 - 0,5V

After inject the power supply with 3V on pin 2 PR159 the electrical current = 0 A. (the tranzistors and dioderemoved from the board as like your sugestions few post above)

Connect the laboratory power supply in series with the resistor as shown on the following picture.
Measure the voltage to ground on pin 2 of resistor PR159 in this case.

matic написав:Connect the laboratory power supply in series with the resistor as shown on the following picture.
Measure the voltage to ground on pin 2 of resistor PR159 in this case.

Soryy but for my undrstand.
Minus concted to the ground on motherboard
Plus 5V with rezistor 10kOhm next to the the PR171

Correct?

Bezel018 написав:Minus concted to the ground on motherboard

True.

Bezel018 написав:Plus 5V with rezistor 10kOhm next to the the PR171

Yes, or any other component on this line (e.g. pin 2 of resistor PR159, pin 1 of diode PD10, pin 2 of resistor PR156, ...).

matic написав:Yes, or any other component on this line (e.g. pin 2 of resistor PR159, pin 1 of diode PD10, pin 2 of resistor PR156, ...).

I conected 5V with rezistor to pin 1 od diode PD10

Power consumpton 0 A
Voltage on Pin 2 on PR159 = 2V

Remove the chip PU5 (MAX1702) from the board and repeat the test suggested in post #16. What is the voltage to ground on pin 2 of resistor PR159 in this case?
Do not connect the charger or battery to the board with the chip PU5 removed.