a1708 problema pp5v

[mvgaminghd]

Hola tengo un problema me llaga una placa que tiene los 20 volts en los fusibles pero no da los 5 volts en pp5v necesito algo de ayuda me tiene perdido

 

[mvgaminghd]

2informatico aparece

 

[2informaticos]

Are you talking about 5V_S4 (L7670)?
Any pulse there at least?
3V3_S5 (L7690) stable?

 

[mvgaminghd]

L7670 shows 0.007 volts both sides

 

[mvgaminghd]

L7670 shows 0.007 volts both sides

L7690 same 0 volts

 

[2informaticos]

Check diode mode to ground on both.

BTW, any reason to check voltage on both sides of a coil?

 

[mvgaminghd]

L7690 435 ohms L7670 542 ohms

 

[2informaticos]

Trigger SMC_ONOFF_L and check for drop pulse at PM_PWRBTN_L, at same time.

 

[mvgaminghd]

5.5 volts

 

[mvgaminghd]

Mirando encontre L2990 explotada reemplazo pero no da voltage en esas lineas tampoco, son esenciales?

 

[2informaticos]

U2800 may bad.
The small redriver chip is also suspect, as always on these models.

 

[mvgaminghd]

okay im trying to replace today its who make ppv5?

 

[2informaticos]

Can you specify what kind of 5V?
S5, S4, S3, S0???

 

[mvgaminghd]

all pp5v rails

 

[2informaticos]

Do you get 3V3/5V_S5 at least?

 

[mvgaminghd]

3v3 present 3.4 volts PP5V_S5 voltage drops and really low

 

[2informaticos]

Diode mode to ground at 5V_S5?

 

[mvgaminghd]

0.430

 

[2informaticos]

Post U7650's basic voltages: 23, 22, 12, 13, 29, 21, 4.

 

[mvgaminghd]

23: 13v
22: 3.3v
12: 0v
13: 0v
29: 0v
21: 0v
4: 0v