• Dell G3 3779, płyta LA-F611P - brak napięcia +PWR_SRC

It is currently 9 January 2025, 23:13

Dell G3 3779, płyta LA-F611P - brak napięcia +PWR_SRC

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#1 Dell G3 3779, płyta LA-F611P - brak napięcia +PWR_SRC

by krisark • 7 January 2025, 16:18
Witam wszystkich,
Dell G3 3779, płyta LA-F611P Rev: 1.00 (A00)
Na płycie był uszkodzony tranzystor PQB02, spuchnięty i pęknięty, rezystancja na PLB01 była w granicy 0,20Ω, tranzystor został wymieniony na nowy AON 6992 oraz odbudowana ścieżka do PLB01.
W tej chwili rezystancja na PLB01 wynosi - 26,20kΩ i rośnie.
Po podłączeniu zasilacza pobór prądu jest 0,000A. Napięcie na rezystorze pomiarowym PRB01 (+SDC_IN) jest poprawne 19,53V, ale napięcie na linii +PWR_SRC jest już 0,40V.
Rezystancja linii +PWR_SRC - 1,95MΩ. Mierzona na PU501 pin -2.
Dlaczego napięcie głównej linii z tranzystora pomiarowego zanika i na +PWR_SRC jest nieprawidłowe?
Ostatnim układem gdzie jest napięcie 19,50V jest PQB07 pin 2 (+CHARGER_SRC).
Nie uruchamia się na baterii oraz nie ładuje.
Płyta była dłubana przez użytkownika wiec może rozlutował jakaś zworkę lub coś wylutował.

Proszę o pomoc w ustaleniu usterki.

Re: Dell G3 3779, płyta LA-F611P - brak napięcia +PWR_SRC

by Google Adsense [BOT] • 7 January 2025, 16:18

#3 Re: Dell G3 3779, płyta LA-F611P - brak napięcia +PWR_SRC

by krisark • 8 January 2025, 10:18
PU501:
pin 2 - 7,25MΩ

Ostatnim tranzystorem gdzie jest napięcie 19,50V jest PQB07 pin 2 (+CHARGER_SRC).
PQB07:
pin 1 - 0,00V
pin 2 - 19,50V
pin 3 - 0,00V
pin 6 - 0,00V

#4 Re: Dell G3 3779, płyta LA-F611P - brak napięcia +PWR_SRC

by matic • 9 January 2025, 08:29
Which charger chip PUB01 is on your board (ISL9538 or ISL95522)?

Measure the following voltages to ground with the power supply connected only (without the battery):
- On pin 4 of transistors PQ3, PQ4.
- On pins 4, 8, 12, 14, 15, 16, 17, 18, 19, 24, 25, 28 of charger chip PUB01.

#5 Re: Dell G3 3779, płyta LA-F611P - brak napięcia +PWR_SRC

by krisark • 9 January 2025, 08:46
matic wrote:Which charger chip PUB01 is on your board (ISL9538 or ISL95522)?
Jest ISL9538H, wymieniłem go już na nowy.
matic wrote:Measure the following voltages to ground with the power supply connected only (without the battery):
- On pin 4 of transistors PQ3, PQ4.
PQ3:
pin 4 - 9,55V
PQ4:
pin 4 - 9,54V

matic wrote:On pins 4, 8, 12, 14, 15, 16, 17, 18, 19, 24, 25, 28 of charger chip PUB01.
PUB01:
pin 4 - 4,84V
pin 8 - 5,17V
pin 12 - 4,85V
pin 14 - 19,95V
pin 15 - 19,94V
pin 16 - 19,93V
pin 17 - 19,73V
pin 18 - 5,16V
pin 19 - 3,71V
pin 24 - 0,00V
pin 25 - 0,00V
pin 28 - 0,00V

Re: Dell G3 3779, płyta LA-F611P - brak napięcia +PWR_SRC

by Google Adsense [BOT] • 9 January 2025, 08:46
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