820-00138 no power no green light

[2informaticos]

Change with known good one.

 

[Djsp]

I removed SMC but the short remains, pp3v42 diode mode is 0.035

 

[2informaticos]

Lift L7095 and check where the low value remains.

 

[Djsp]

it stays on pin 2 of L7095

 

[2informaticos]

Many chips connected there, not easy job.
Inspect U1900/50, U3740, U7001, U4650, U4850, U5110, J5250, J6100 for coorosion.
If nothing strange, then remove one by one and check diode mode reading each time.

Also take a look at filter caps placed on 3V42_G3H.

 

[Djsp]

I removed U1900 and the value rose to 0.109 and he is the culprit

 

[2informaticos]

The board works now?
When board is cooled down, usual value is approx 0.300 at 3V42_G3H.

 

[Djsp]

I have to reball the smc and replace u 1900

 

[Djsp]

Here I am! So I reballed to SMC now I get ppbus_g3 and 3v42, it starts for 5 seconds and then stops. So for 3 times, and I have orange light even with the battery not connected

 

[2informaticos]

Did you try SMC bypass?
Get known good battery for test in normal way; these boards may have weird issues without battery.

 

[Djsp]

Does it work there is the dong there is no backlight but OS X charge is it the spi rom?

 

[2informaticos]

Is not BIOS problem.
If board stays on in SMC bypass, must a problem with some I/V sensor.
Check first if AVREF_SMC is present.

Remember to use 85W Magsafe 2 charger!!!

 

[Djsp]

AVREF_SMC is present

 

[2informaticos]

Start the board in SMC bypass mode and check all I/VSENSE outputs from page 44.
Post their levels here.

 

[Djsp]

I wanted to bypass with pads near the keyboard connector and now I'm in the starting situation again pp_bus 12.25 and pp3v42 and 3.36 but on pin 2 of L7095 first it's normal

 

[2informaticos]

I'm not sure about what you mean with L7095.

If board stays on, check what I've said.
Start with C5414/21/41.

 

[Djsp]

Unfortunately I don't get the green light and the fan doesn't turn Ppbus_g3 remains at 12.25 and pp3v42 3.37 pin 2 of l7095 I get: smc_bc_acok, smc_reset_l pp1v2_s5_smc, I checked the pull-up resistors and the crystal, is bad SMC ?

 

[2informaticos]

Is normal to lose green light on SMC bypass mode.
But fans should start with full speed.

Do you get again low resistance to ground at L7095?
Post the exact value in diode mode (red to ground).

 

[Djsp]

I don't think the L7095 is 0.341 diode mode, I don't even get the SMC bypass and green light anymore

 

[2informaticos]

Post again basic voltages; 3V42_G3H, PPBUS_G3H, SMC_RESET_L, 3V3_S5.