A1466 820-00165-A no power

[hgoncalves]

Hi,

I have an A1466 820-00165-A with no power. It has green light, and no fan spin.

I have no hiustory about it.

PPBUS_G3H = 1.821V, and 0.156 on diode reading.

Already tried new DC board, and new charger.

Can you help?

 

[2informaticos]

Post U7100 basic voltages; pins 1, 2, 3, 9, 12, 13, 15, 17, 19, 20, 27.
Check resistance between pins 17/18 and 27/28.

 

[hgoncalves]

Hi,

U7100:
1 = 0V
2 = 15.45V
3 = 4.167V
9 = 0.111V
12 = 3.343V
13 = 3.4V
15 = 0.069V
17 = 1.8V
19 = 5V
20 = 5V
27 = 15.28V

Resistance between:
17/18 = 3.2 ohm
27/28 = 19.9 ohm

 

[2informaticos]

Remove F7140 and check C7140 voltage.

You may need to change Q7130.
Be sure C7125 is good; check its traces too.

 

[hgoncalves]

C7140 has 8.57V, without F7140.
C7125 seams to be OK, and the traces are OK.

Changing Q7130 had the same result.

With F7140 soldered PPVBAT_G3H_CHGR_REG cames back to 1.8V

Should I inject voltage on PPBUS_G3H to check for heat? It has 0.178 on diode reading.

 

[2informaticos]

No need to change Q7130, if get correct voltage without F7140.
Check diode mode to ground on all coils; compare with PPBUS_G3H.

 

[hgoncalves]

PP5V_S4RS3 is shorted. 0.20 diode to ground, checked on L7520, and it had a bit of corrosion under L7520. The comparison diode mode to ground is 0.340.
Can inject 1V to check what component is shorted?

 

[hgoncalves]

After inject voltage on PP5V_S4RS3 , I notice that U7600 was getting hot, and so I've replaced it. Now PP5V_S4RS3 has 0.430 on diode to ground reading, but still no power on, and PPBUS_G3H is 1.8V again.

L7630 has the same diode resistance to ground has PPBUS_G3H (0.130)

L7320 has 0.014

L7310 has 0.014

 

[2informaticos]

Check diode mode between ppbus_g3h and any coil.

 

[hgoncalves]

Diode mode between PPBUS_G3H and L7130 / L7630 is 0.001.

Btween other coils it has values around 0.400, except L7320 and L7310 witch is 0.220

 

[2informaticos]

"Diode mode between PPBUS_G3H and ... L7630 is 0.001"
And you still applied power on the board.
"Check diode mode to ground on all coils; compare with PPBUS_G3H."
Pay more atention when you read the posts.

Change Q7630...

 

[hgoncalves]

Hi,

After replacing Q7630, the short is gone. However, the mac tries to boot, has fan spin, reaches 0.650A and powers off (10mA).
Alreay tried new CLEAN ME without success
Any idea?

 

[2informaticos]

PCH is bad probably.

PLT_RESET_L goes high?
Did you try SMC bypass?

 

[hgoncalves]

Hi.

PLT_RESET_L goes to 3.3V and then 0V

SMC bypass has the same result.

Do you think it is PCH?

 

[2informaticos]

Overvoltage went to PCH for sure, throuh Q7630.
Sometime it survives; seems is not the case here.