• Apple A2141 820-01700-a Brak podświetlenia

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Apple A2141 820-01700-a Brak podświetlenia

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#1 Apple A2141 820-01700-a Brak podświetlenia

by pehol193 • 8 July 2025, 07:51
Cześć, jak w temacie obraz jest widoczny, ale brak podświetlenia matrycy.

Co zrobione:
- Podmiana Q8400, U8400 2X.
- Podmienione całe skrzydło matrycy.
- Konektor matrycy podmieniony.
Napięcia:
Q8400
n3. 12V
n4. 12v
n5. 0,5v
R8444 5V
R8442 3,3V

Proszę o dalsze sugestie, nie widać śladów zalania itp.

Re: Apple A2141 820-01700-a Brak podświetlenia

by Google Adsense [BOT] • 8 July 2025, 07:51

#2 Re: Apple A2141 820-01700-a Brak podświetlenia

by matic • 8 July 2025, 10:08
Hello!

- Measure the resistances to ground on both pins of diodes D8410, D8450.

Measure the following voltages to ground when the machine is turned on with the matrix connected:
- On pin 1 of resistor R4896.
- On pins 5, 9, 10, 11, 12, 15, 16, 17, 18 of chip U8400.

#3 Re: Apple A2141 820-01700-a Brak podświetlenia

by pehol193 • 8 July 2025, 11:51
-diodes:
D8410 n1.1,5MΩ n2. 2MΩ
D8450 n1. 50KΩ n2. 1,1MΩ

Measure the following voltages to ground when the machine is turned on with the matrix connected:
- On pin 1 of resistor R4896 is 1,8V

U8400:
n5. 5v
n9. 12,62v
n10. 12,62v
n11. 0,2v
n12. 0v
n15. 5v
n16. 5v
n17. 3,3v
n18 . 5v

#4 Re: Apple A2141 820-01700-a Brak podświetlenia

by matic • 9 July 2025, 08:21
Also measure the following voltages to ground, when the machine is turned on with the matrix connected:
- On pin 2 of resistor R8520.
- On pin 5 of chip U8500.

#5 Re: Apple A2141 820-01700-a Brak podświetlenia

by pehol193 • 9 July 2025, 09:09
- On pin 2 of resistor R8520. 3,3v
- On pin 5 of chip U8500. 0,07v

#6 Re: Apple A2141 820-01700-a Brak podświetlenia

by matic • 9 July 2025, 11:19
- Measure the resistance to ground on pin 5 of chip U8500 with the matrix connected.

- If the resistance is high (in the kΩ range or greater), measure the voltages to ground on pins 1, 2, 7 of chip U8500, when the machine is turned on with the matrix connected.

#7 Re: Apple A2141 820-01700-a Brak podświetlenia

by pehol193 • 9 July 2025, 11:35
resistance to ground on pin 5 of chip U8500 is 3kΩ
chip U8500

n1. 5v
n2. 3,3v
n7. 0,5v 15MΩ

#8 Re: Apple A2141 820-01700-a Brak podświetlenia

by matic • 9 July 2025, 11:55
Replace the chip U8500 (SLG5AP1443V).

#9 Re: Apple A2141 820-01700-a Brak podświetlenia

by pehol193 • 9 July 2025, 12:12
Po wymianie brak podświetlenia, pomiary takie same

#10 Re: Apple A2141 820-01700-a Brak podświetlenia

by matic • 9 July 2025, 12:23
For the reference, measure the voltages to ground on pins 1, 2, 5, 7 of chip U8501.

Re: Apple A2141 820-01700-a Brak podświetlenia

by Google Adsense [BOT] • 9 July 2025, 12:23
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