A1398 3332-A no power

[hgoncalves]

Hi,

I have an A1398 820-3332-A that has no power.

It pulls 100mA from bench PSU, I have green light on the charger, but no power or fan spin.

All Vcore voltages are missing.

Can you help?

 

[2informaticos]

What voltages do you get in power on sequence?
Detect something on the big coils?

 

[hgoncalves]

Hi,

I get all states of PP3 and PP5 and PP1V8 correctly.

On the big coils (CPU and GPU) I don't get any voltages

 

[2informaticos]

Please, list coils and voltages.
No idea if you get DDR and PCH voltage, for example.

 

[hgoncalves]

Sorry.

L3895 = 0.620V
L7770 = 1.5V
L7220 = 5V
L7030 = 12.57V
L7330 = 1.3V
L9830 = 1V
L7260 = 3.3V
L8360 = 0V
L8310 = 0V
L7720 = 1.8V
L7630 = 1V
L7100 = 0.012V
L7530 = 0V
L7520 = 0V
L7510 = 0V
L7550 = 0V
L7560 = 0V
L8960 = 0V
L8930 = 0V

 

[2informaticos]

Be sure to check all voltages properly; output pin of the coils.
L7330 should be 1.5V.

L7100 should get voltage, if PVCCSA_EN is present; comes from PM_SLP_S3_L (present for sure).

 

[hgoncalves]

On PVCCSA_EN I get 3.259V (read on R7987), but on L7100 I iget 0.012V on both pins.

On L7330 I get:
Pin 1 = 1.354V
Pin 2 = 1.345V

 

[2informaticos]

Any idea about resistance to ground at L7100?
Compare with good board.
Post U7100 nasic voltages; pins 19, 20, 15.
Check R/C7130.

 

[hgoncalves]

L7100 has 5.4 ohm resistance to ground (not sure if the value is ok, because I don't have a working board here).

U7100:
19 = 5.036V
20 = 5.039V
15 = 3.259V
16 = 0V

R/C1730 looks OK. However, on C7130, I have 4.716V on pin1, and 0V on pin2.

 

[2informaticos]

Resistance to ground is good.
Change U7100.
Maybe need to change Q7100 too.

 

[hgoncalves]

Hello,

I've replaced both U7100 and Q7100 but stil doesn't power on.

 

[2informaticos]

Still no voltage at L7100?

 

[hgoncalves]

L7100 has 0.038V on both pins, and Pin 16 of U7100 also has 0.038V

 

[2informaticos]

Check all components and traces related with U/L7100.
Pay atention to R7151/52 and R/C7130.

 

[hgoncalves]

Hi,

It was R7151 that was bad. After replacement, now it powers on. However, I only get image on the external monitor. I already tried a known good display, but no image.

 

[2informaticos]

Do you get 5V at J9000?
At least in the first few seconds, when hear the chime.
LCD_HPD must go high at same time.

 

[hgoncalves]

I have 5V (PP5VR3V3_SW_LCD) on J9000, but LCD_HPD is always at 0V

PPVOUT_S0_LCDBKLT = 0V

F9700= 12.56V

 

[2informaticos]

That is really srange; do you check at both pins of R9000?
PCH requires LCD_HPD signal high, to maintain LCD_PWR_EN.

 

[hgoncalves]

Yes, I recheked again and I have 0V on R9000 (both pins) and on pin 9 of J9000
LCD_PWR_EN = 3.315V

 

[2informaticos]

If LCD_HPD stays low, 5V should disappear from J9000 after few seconds.