• Lenovo IdeaPad 3 15ADA05 Laptop - Type 81W1 - Nie Podświetla Matrycy po Wymianie

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#1 Lenovo IdeaPad 3 15ADA05 Laptop - Type 81W1 - Nie Podświetla Matrycy po Wymianie


by wojtekk78 13 June 2024, 13:06
Witam,
Trafił do mnie laptop:
Lenovo IdeaPad 3 15ADA05 Laptop - Type 81W1
Oznaczenia z płyty gł.:
GS450&GS550&GS750 NM-C821
Rev: 1.0
2019-12-05

Miał mocno zbitą matrycę. Sprawdzić go mogłem tylko na monitorze zewnętrznym, przed naprawą, bo ta zbita tylko na kilka sekund się zaświeciła i gasła (pajęczyna, nic na niej nie było widać).
Po wymianie matrycy (wczoraj) na nową miałem taki motyw, że tylko przez kilka sekund mam na niej obraz potem gaśnie, ale jak się przyjrzeć pod światło to widać że jest ekran logowania, ale nie ma podświetlania. Na monitorze zewnętrznym wszystko jest ok. Wymieniłem na 2 inne matryce, ale bez zmian, zawsze tylko przez kila sekund był na nich obraz. Taśmy od matrycy innej na podmiankę nie mam, no ale nie specjalnie mi się wydaje że to ona powoduje problem, klient to kolega i twierdzi że przed zbiciem matrycy nic takiego nie występowało.
Myślałem, że może coś z Windowsem, ale jak odpalam system z pendrive, mam tak samo, poza tym na BIOS to samo. Dzisiaj od rana natomiast nawet na te kilka sekund się nie zapala obraz, tylko jak się przyjrzeć pod światło to widać że jest ekran logowania.

Jest to możliwe, że jednak taśma jest uszkodzona? Czy problem po stronie płyty głównej?
Sporo matryc już wymieniłem, ale jeszcze takiego motywu nie miałem ( bateria oczywiście wyjęta w pierwszej kolejności).

Nie mam pomysłu co jeszcze posprawdzać. Czy zamawiać od razu taśmę matrycy?

Re: Lenovo IdeaPad 3 15ADA05 Laptop - Type 81W1 - Nie Podświetla Matrycy po Wymianie


by Google Adsense [BOT] 13 June 2024, 13:06

#2 Re: Lenovo IdeaPad 3 15ADA05 Laptop - Type 81W1 - Nie Podświetla Matrycy po Wymianie


by matic 13 June 2024, 14:44
Hello!

Measure the voltage to ground on pin 1 of LVDS connector JEDP1, when there is no backlight. There should be 20V.
If this voltage is missing or too low, the fuse F2 is very likely damaged.

If this voltage is fine, measure the voltages to ground on pins 15, 16 of LVDS connector JEDP1, when there is no backlight.

#3 Re: Lenovo IdeaPad 3 15ADA05 Laptop - Type 81W1 - Nie Podświetla Matrycy po Wymianie


by wojtekk78 14 June 2024, 09:35
Thank you, I will try to measure the voltages on these pins today.

Edit:
I have measured the voltages and I have:
Pin 1 to ground = 20,3V
Pin 15 to ground = 3,3V
Pin 16 to ground = 0V

Edit 2:
Measured resistance, on a switched-off laptop:
Pin 15 to ground = 9kΩ
Pin 16 to ground = shows differently, increasing from 12kΩ to 17.5kΩ. But I also had a value in the region of 25kΩ.

#4 Re: Lenovo IdeaPad 3 15ADA05 Laptop - Type 81W1 - Nie Podświetla Matrycy po Wymianie


by wojtekk78 17 June 2024, 13:02
matic wrote:Hello!

Measure the voltage to ground on pin 1 of LVDS connector JEDP1, when there is no backlight. There should be 20V.
If this voltage is missing or too low, the fuse F2 is very likely damaged.

If this voltage is fine, measure the voltages to ground on pins 15, 16 of LVDS connector JEDP1, when there is no backlight.


Hi,
I have measured the voltages in the post above.
I had 0V on Pin 16 - is this the problem of no backlighting?

#6 Re: Lenovo IdeaPad 3 15ADA05 Laptop - Type 81W1 - Nie Podświetla Matrycy po Wymianie


by matic 17 June 2024, 18:28
Measure the voltage to ground on pin 2 of transistor QC8 in both cases - when the backlight is working and when it's not.

Re: Lenovo IdeaPad 3 15ADA05 Laptop - Type 81W1 - Nie Podświetla Matrycy po Wymianie


by Google Adsense [BOT] 17 June 2024, 18:28
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