A1398 820-3787-A no power

[hgoncalves]

Hi.

I have an A1398 820-3787-A with no green light and no power.

It had U7190 burnt and I've replaced it.

Now, P5V1_VIN = 19.7V (shoulden't it be only 5V?)

PPDCIN_G3H_CHGR was shorted, and after replacing Q7130 the short is gone.

However, i don't have no power and no green light on charger.

PP3V42_G3H = 3.4V
PPDCIN_G3H = 20V

PPBUS_G3H = 0V and 0.446 on diode reading

Can you help?

 

[2informaticos]

Post U7100 basic voltages; pins 1, 2, 3, 9, 12, 13, 14, 15, 17, 19, 20, 27.

 

[hgoncalves]

U7100:
1 = 18.53V
2 = 0.004V
3 = 4.7V
9 = 0.001V
12 = 3.4V
13 = 3.4V
14 = 0.007V
15 = 0.053V
17 = 0.041V
19 = 0.192V
20 = 0.205V
27 = 0.535V

 

[2informaticos]

Are you sure about pins 1 & 2?

Check R7180/81 and R7185/86 values; onboard, ohm scale.
Also be sure they have good traces.

 

[hgoncalves]

Hi.

Yes, I've just recheked them:
U7100:
1 = 18.53V
2 = 0.004V

R7180 = 99.9 kohm
R7181 = 61.9 kohm
R7185 = 468.3 kohm
R7186 = 329.5 kohm

All traces have continuity

 

[2informaticos]

"2 = 0.004V"
Check for short there.

Post Q7010 voltages.

 

[hgoncalves]

"2 = 0.004V"
Check for short there.
U7100 was shorted. After replacing it, now I have:
1 = 0V
2 = 4.7V
3 = 4.7V
9 = 0.033V
12 = 3.4V
13 = 3.4V
14 = 3.3V
15 = 0.053V
17 = 12.54V
19 = 5.4V
20 = 5.4V
27 = 17.75V


My shematic seams to be wrong, causeI can't find Q7010 on this board (seams a different chip there with 8 pins)

 

[2informaticos]

"2 = 4.7V"
Still bad.

"U7100 was shorted."
At least one of R/D7105 got burnt.

 

[hgoncalves]

R7105 was bad. After replacing it, I've got the correct ohm value. D7105 seams to be OK.

CHGR_DCIN_D_R = 19.75V

However, Still the same behavier.

 

[2informaticos]

Post again mentioned U7100's pins.
Also post U7010 voltages; use lines name on the boardview!
Q7010 has several adjacent components to use as test points.

 

[hgoncalves]

Hi.

Can't find U7010 on this board. I think it was a typo.

U7100:
1 = 0.002V
2 = 19.74V
3 = 4.7V
9 = 0.033V
12 = 3.4V
13 = 3.4V
14 = 3.3V
15 = 0.053V
17 = 12.54V
19 = 5.4V
20 = 5.4V
27 = 16.30V

Q7010:
PPDCIN_G3H = 19.99V
PPDCIN_G3H_ISOL = 19.99V
DCIN_ISOL_GATE_R = 6.65V
DCIN_ISOL_GATE = 6.65V
PP20V_DCIN_CONN_R = 19.86V

 

[2informaticos]

"Can't find U7010"
Who asked you about that???

So you have correct 3V42_G3H and PPBUS_G3H.
No other basic voltages present?

 

[hgoncalves]

Hi,

You've asked for U7010 voltages in previous reply. I guess it was a distraction.

It seams that sometimes the mac reboots randomly.

PPBUS_G3H = 12.56V (stable until reboots)
3V42_G3H = 3.4V (stable until reboots)
PP3V3_S5 = 3.3V (stable until reboots)

PP5V_S5 = 5V, but sometimes oscilates bettwen 2V and 5V. Other times goes to 0V for a long time.

 

[2informaticos]

Yeah sorry, just saw it now.
But I mentioned Q7010 more times; even in the same post with the typo.

Trigger SMC_ONOFF_L and check for frop pulse at PM_PWRBTN_L.
If catch it, check for pulse at PM_SLP_S4_L b (at same time).

Tried SMC bypass?

 

[hgoncalves]

Hi,

I haven't tried SMC Bypass (sorry, forgeted), but it powers on in SMC Bypass.

When triggering SMC_ONOFF_L, i have drop pulse at PM_PWRBTN_L, but no pulse at PM_SLP_S4_L. However, I have no green light on charger

Shall I replace SMC?

 

[2informaticos]

This machine requires 85W charger.
If no (charged) battery connected, will not power up with 45/60W charger alone; ONLY in SMC bypass!

 

[hgoncalves]

Hi.

After using an original 85W charger, the mac now powers on, but it dosen't charge the battery, and has no green light on the charger.

Shall i replace SMC?

 

[2informaticos]

Did you test with known good DCIN board?
Check U7000/1 voltages.

 

[hgoncalves]

Hi,

Yes. I've tried with a good DCIN board.

Right now i don't even have PP3V42_G3H

PPDCIN_G3H = 19.9V

PPBUS_G3H = 0V, and 0.454 diode reading
PP3V42_G3H = 0V, and 0.578 diode reading
PP5V_S5 = 0V, and 0.506 diode reading

PP3V3_S5 = 0V, and 0.152 on diode reading

U7000:
1= 0V
2= 0V
3= 0V
4= 0V
5= 0V

U7001:
1= 0V
2= 0V
3 = 0V
4= 0V
5= 0V

 

[2informaticos]

Any reason to check other voltages, when missing 3V42_G3H and PPBUS_G3H?
Put some logic in your job and don't waste time.

Check Q7010 voltages.