Samsung NP350V5C QCLA4 LA-8861P REV: 2.0 Nie włącza się.

Witam,
Model: Samsung NP350V5C
Płyta: QCLA4 LA-8861P REV: 2.0
KBC: ENE KB9012QF
CPU: i5-3210MM (SR0MZ)
GPU: 216-0833000
Kość: WINBOND 25Q32BVSIG

Laptop się nie włącza. Zero reakcji. Brak 3,3V na przycisku "power". Pomiary bez ram i procesora.
Płyta nie pobiera żadnego prądu.
Rezystancja na cewkach:
PL202 - 1,15 kΩ
PL703 - 4,4 Ω
PL514 - 50 kΩ
PL801 - 40 kΩ
PL352 - 140 Ω
PL1000 - 80 Ω
PL182 - 28 kΩ
PL402 - 37 Ω
PL201 - 600 kΩ
PL512 - 1 kΩ
PL511 - 1 kΩ
PL152 - 400 Ω
PL332 - 15 Ω

Po podłączeniu zasilacza napięcie pojawia się tylko na cewce PL202 - 2,4V

Bardzo proszę o sugestie.

Bezel018 napisał(a):PL332 - 15 Ω
PL352 - 140 Ω

Hello!
Are these two measurements correct?
If so, open the jumpers PJ332, PL352 and measure the resistances to ground on both pads of these jumpers.

matic napisał(a):Hello!
Are these two measurements correct?
If so, open the jumpers PJ332, PL352 and measure the resistances to ground on both pads of these jumpers.

I remesured once again after losing all current of the board. Now looks like:
PL332 - 16 kΩ
PL352 - 19 kΩ

When I plug in power supply and disconnect after few seconds it the value on the coils looks like in post 1...

Bezel018 napisał(a):Po podłączeniu zasilacza napięcie pojawia się tylko na cewce PL202

Is there no voltage even on the coil PL201?
If so, measure the voltages to ground on pins 1, 4, 8 of transistors PQ203, PQ205.

matic napisał(a):Is there no voltage even on the coil PL201?

PL201 - 19,38 V

matic napisał(a):If so, measure the voltages to ground on pins 1, 4, 8 of transistors PQ203, PQ205.

PQ203:
1 - 19,38 V
4 - 25,25 V
8 - 19,38 V

PQ205:
1 - 19,38 V
4 - 25,25 V
8 - 19,38 V

Measure the voltages on pins 1, 3, 6, 8, 9, 13, 16, 17, 22 of PU330.

Measure the voltages to ground on pins 1, 3, 6, 8, 9, 13, 16, 17, 22, 23 of chip PU330.

matic napisał(a):Measure the voltages to ground on pins 1, 3, 6, 8, 9, 13, 16, 17, 22, 23 of chip PU330.

1 - 0 V
3 - 0 V
6 - 0 V
8 - 0 V
9- 0 V
13 - 3,2 V
16 - 19,39 V
17 - 0 V
22 - 0 V
23 - 0 V

Measure the resistance to ground on pins 3, 8, 17 of PU330.
f the resistance is high replace PU330.

Machine napisał(a):Measure the resistance to ground on pins 3, 8, 17 of PU330.

3 - 110 kΩ
8 - 4 Ω
17 - 315 kΩ

Machine napisał(a):f the resistance is high replace PU330.

Should I replace the chip? If yes what is the chip? RT8205L?

Desolder PU330 and inject 3v on pin 8, max 500mA, the KBC will certainly heat up and needs to be changed.

Desolder PU330 and inject 3v on pin 8, max 500mA, the KBC will certainly heat up and needs to be changed.

I desoldered the PU330. I set the 3V and 500mA. The current consumption is 0.120 A.
The KBC chip is cold.

Remeasure the resistance to ground on pad 8 on the place of chip PU330 (with the chip removed from the board).

Remeasure the resistance to ground on pad 8 on the place of chip PU330 (with the chip removed from the board).

41 Ω

Zobacz na ten film, ja swojego laptopa naprawiłem w ten sposób. To chyba standardowa usterka w tym modelu:
https://youtu.be/X0HCzlgCUbk?si=yEHZ-FpXUE9zlvHU

samsung-np350v5c-qcla4-la-8861p-rev-2-0-nie-wlacza-sie-t71909.html

Bezel018 napisał(a):

Remeasure the resistance to ground on pad 8 on the place of chip PU330 (with the chip removed from the board).

41 Ω

This resistance is still too low.
Repeat the short circuit test from post #12. This time limit the voltage to 3.3V, wait about 20 minutes and then check if anything is slightly warm on the motherboard.
Pay special attention to the KBC and UCL1 chip.

This resistance is still too low.
Repeat the short circuit test from post #12. This time limit the voltage to 3.3V, wait about 20 minutes and then check if anything is slightly warm on the motherboard.
Pay special attention to the KBC and UCL1 chip.

The UCL1 is little warm.
About 30-31 degrees.

Remove the chip UCL1 from the board and remeasure the resistance to ground on pad 8 on the place of chip PU330.
If the resistance will increase to a high value (kΩ range or greater), the chip UCL1 is damaged and needs to be replaced.

Remove the chip UCL1 from the board and remeasure the resistance to ground on pad 8 on the place of chip PU330.
If the resistance will increase to a high value (kΩ range or greater), the chip UCL1 is damaged and needs to be replaced.

After removed the UCL1 I had about 80 kOhm. I replaced the UCL1 for the new one. I soldered the PU330 back and board turn on but have not a display. The diodes on power switch shine constantly and sometimes blinkins. I try to another memory RAM. Still the same.

Check your solder joints on all pins of chip UCL1.
If the solder joints are fine, measure the voltages to ground on pins 2, 3, 8, 9, 10, 11, 14, 15 of chip UCL1, when the machine is turned on (power LED is turned on).