Salta al contenuto principale
Aiuto

Versione corrente di: zzz ,

Testo:

This is all wrong. You're talking about buying replacement chips without even having a schematic or a boardview. How can you know what to replace without even knowing where to measure??? How do you know the LED driver is bad?
 
Get a schematic and a boardview for 820-3476, then answer the following questions before further guessing.
 
1) Do you have 2.7v to 3v enable signal on pin 17 of U7700?
 
2) Do you have 5v on pins 5 and 18? Of18 of U7700?
2) Do you have 5v on pins 5 and 18? Of18 of U7700?
 
3) Is R7733 0 ohms?
 
4) Is feedback network between R7731 and R7732 functioning properly? Traces to resistors good? Resistors themselves good?
 
5) What voltage do you have on backlight output, pin 1 of LCD connector? 0v? 12v? 20v? 27v?

Stato:

open

Post originale di: zzz ,

Testo:

This is all wrong. You're talking about buying replacement chips without even having a schematic or a boardview. How can you know what to replace without even knowing where to measure??? How do you know the LED driver is bad?

Get a schematic and a boardview for 820-3476, then answer the following questions before further guessing.

1) Do you have 2.7v to 3v enable signal on pin 17 of U7700?

2) Do you have 5v on pins 5 and 18? Of U7700?

3) Is R7733 0 ohms?

4) Is feedback network between R7731 and R7732 functioning properly? Traces to resistors good? Resistors themselves good?

5) What voltage do you have on backlight output, pin 1 of LCD connector? 0v? 12v? 20v? 27v?

Stato:

open