Sony Vaio PCG-7131M - nie uruchamia się, brak 3V/5V.

Leciwy laptop Sony Vaio z płytą o oznaczeniu MBX-223, nie uruchamia się. Po podaniu napięcia 19,5V przez ok. 10 sekund jest pobór 120 mA, potem spada do 0. Na termowizji przez te 10 sekund grzeje się przetwornica 3V/5V, stabilizator PU9 (AT5208-3.3KER) oraz delikatnie KBC. Brak zwarcia na PU9 na pinach 1, 3, 5. Na wyjściu PU9 jest 3,28V. Natomiast 5V_LDO = 4,96V. Przetwornica to SN0608098RHBR. Sygnał ALW_ON z KBC wynosi 0,07V.
Rezystancja na cewkach przetwornicy:
PL16: 25 kΩ
PL17: 19 kΩ
Przez te 10 sekund napięcie na:
PL16: 0,1V
PL17: 0,7V
Potem spadają na 0V.

Uszkodzona będzie przetwornica czy KBC ? Jak to bardziej precyzyjnie sprawdzić ?

Hello!

Plug the power supply to the DC socket and perform the following measurements:
- Measure the voltages to ground on pins 1, 4, 8 of transistors PQ1, PQ2.
- Measure the voltages to ground on pins 1, 2, 3, 4, 5, 7, 8, 10, 13, 24, 27, 28 of charger chip PU3.

Uszkodzona będzie przetwornica czy KBC ? Jak to bardziej precyzyjnie sprawdzić ?
Pod sygnał en (tu masz dwa oddzielne) en1,en2 podajesz 3,3v i musisz mieć stabilne wyjście.

matic написав:Plug the power supply to the DC socket and perform the following measurements:
- Measure the voltages to ground on pins 1, 4, 8 of transistors PQ1, PQ2.
- Measure the voltages to ground on pins 1, 2, 3, 4, 5, 7, 8, 10, 13, 24, 27, 28 of charger chip PU3.

My measurements are as follows:
PQ1
1: 19,49V
4: 13,16V
8: 19,49V
PQ2
1: 19,48V
4: 13,14V
8: 19,48V

PU3
1: 3,3V
2: 19,49V
3: 19,49V
4: 13,2V
5: 2,71V
7: 0V
8: 2,72V
10: 3,3V
13: 0V
24: 0V
27: 0V
28: 19,50V

ado написав:Pod sygnał en (tu masz dwa oddzielne) en1,en2 podajesz 3,3v i musisz mieć stabilne wyjście.

Zrobiłem jak napisałeś i pojawia się 3V i 5V. Nic się nie grzeje.

LordVader написав:

ado написав:Pod sygnał en (tu masz dwa oddzielne) en1,en2 podajesz 3,3v i musisz mieć stabilne wyjście.

Zrobiłem jak napisałeś i pojawia się 3V i 5V. Nic się nie grzeje.

I hope you removed the resistors PR98 and PR198 from the board before doing this, otherwise there is a risk to damage some components on the board this way.

Measure the following voltages to ground:
- On pins 2, 4 of transistor PQ4.
- On pins 3, 5 of transistor PQ33.
- On pins 1, 2 of chip U15.
- On pins 15, 44, 99, 101 of KBC chip.

matic написав:I hope you removed the resistors PR98 and PR198 from the board before doing this, otherwise there is a risk to damage some components on the board this way.

I didn't remove those resistors, because I didn't know that. I'm a beginner and I don't know everything yet.

My measurements:
PQ4
2: 0V
4: 0V

PQ33
3: 18,84V
5: 0V

PU15
1: 0V
2: 5,8V

KBC
15: 0V
44: 1,8V
99: 0V
101: 3,3V

- Remove the chip PU15 from the board and remeasure the voltage to ground on pad 1 on the place of PU15.
- Remeasure the voltages to ground on pins 15, 99 of KBC chip with the lid open (without chip PU15).

matic написав:I hope you removed the resistors PR98 and PR198 from the board before doing this, otherwise there is a risk to damage some components on the board this way.

Which components could be damaged ?

Measurements without PU15:
PU15:
1: 4.96V
2: 5,98V

KBC:
15: 0V
99: 3,27V

LordVader написав:Which components could be damaged ?

Diodes PD1, PD5, PD30, transistors PQ4, PQ33, chip PU15.
Chip PU15 seems damaged. This chip is for the under-voltage protection, so you can test the board without this chip.

- Measure the resistance to ground on pin 14 of chip PU19.
- Measure the resistance to ground on pin 15 of KBC chip.

I connected the DC plug, there is 3V and 5V on PU19, but only for 10 seconds.

PU19
14: 31 kΩ
KBC
15: 33 kΩ

LordVader написав:I connected the DC plug, there is 3V and 5V on PU19, but only for 10 seconds.

Do you think there is 3V and 5V on coils PL16, PL17 for 10 seconds?
If so, measure the voltages to ground on pins 15, 106 of KBC chip within these 10 seconds.

matic написав:If so, measure the voltages to ground on pins 15, 106 of KBC chip within these 10 seconds.

KBC:
15: 3,30V --> 10sec --> 0V
106: 3,32V --> 10sec --> 0V

Does the machine respond to pressing on the power button within these 10 seconds?

matic написав:Does the machine respond to pressing on the power button within these 10 seconds?

The laptop turns on when I press the power button, but there is no picture.

LordVader написав:The laptop turns on when I press the power button, but there is no picture.

Measure the voltages to ground on all coils, when the machine is turned on.

matic написав:Measure the voltages to ground on all coils, when the machine is turned on.

PL16: 5,05V
PL17: 3,34V
PL5: 1,05V
PL8: 1,04V
PL19: 1,10V
PL18: 1,05
PL6: 1,51
PL2: 0V

The current consumption is 10mA for the first 10 seconds, then 5mA.
When I start my laptop it works for 2 minutes and then shuts down.

Reflash both (MAIN + EC) BIOS chips. Don't forget to save the old dumps.
Note that the new BIOS dumps should be from the same board (in your case probably MBX-223, M960).
The dump from the board MBX-223, M970 is not suitable for your board.

matic написав:Reflash both (MAIN + EC) BIOS chips. Don't forget to save the old dumps.
Note that the new BIOS dumps should be from the same board (in your case probably MBX-223, M960).
The dump from the board MBX-223, M970 is not suitable for your board.

matic, the computer works, thank you very much.