• Lenovo A475 NM-B351 Rev 1.0 Nie uruchamia się

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Lenovo A475 NM-B351 Rev 1.0 Nie uruchamia się

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#1 Lenovo A475 NM-B351 Rev 1.0 Nie uruchamia się

by Evdion • 15 October 2024, 16:14
Witam, walczę z Lenovo A475 na AMD A12. Komputer się nie uruchamia, nie startuje zasilanie procesora, ramu oraz spi na 8n.; brak reakcji na włącznik, mignie tylko 3x dioda na przycisku.
Zauważyłem jeszcze zwarcie między drenem a źródłem na PQ402, PQ404, PQ405, PQ407, PQ408; po wylutowaniu pierwszych trzech okazały się one sprawne a zwarcie nie ustąpiło, spadek na płycie po wylucie wynosi 0,020V dren-źródło. Proszę o pomoc w diagnozie.

Wstępne pomiary na dławikach:
PL101 46KΩ 19,95V
PL102 10KΩ 0,3V
PL201 2,1KΩ 3,3V
PL202 5,2KΩ 5,2V
PL701 535Ω 0V
PL401 10,7Ω 0V
PL406 15Ω 0V
PL409 15Ω 0V
PL301 240Ω 0V
UC8M1 8n. 0,8MΩ 0V
U186 8n. 42KΩ 3,2V
Pobór prądu przez płytę to 0,031A.

Re: Lenovo A475 NM-B351 Rev 1.0 Nie uruchamia się

by Google Adsense [BOT] • 15 October 2024, 16:14

#2 Re: Lenovo A475 NM-B351 Rev 1.0 Nie uruchamia się

by matic • 21 October 2024, 08:48
Evdion wrote:Zauważyłem jeszcze zwarcie między drenem a źródłem na PQ402, PQ404, PQ405, PQ407, PQ408
Hello!
What's an actual resistance between drain and source of these transistors?

Re: Lenovo A475 NM-B351 Rev 1.0 Nie uruchamia się

by Google Adsense [BOT] • 21 October 2024, 08:48
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