820-00687 doesn't seem to turn on

[nik1981]

I have an A1534 which came in with a broken screen and a flat battery. The screen assembly was replaced and it doesn't seem to have any signs of life apart from the led on the board.

I've checked the basics but I'm at a loss. It was with another company first but they apparently "hadn't touched it" (Although the trackpad connector flap had gone missing)

8.63v PPBUS_G3H
14.67v PPVIN_G3H_P3V3G3H
8.63v PPBUS_S5_HS_COMPUTING_ISNS
14.69v PPVBUS_LIO
14.69v PPDCIN_G3H
3.29v PP3V3_G3H
3.29v PP3V3R3V0_AON
4.96v PP5V_G3H

Any ideas where to start from here?

 

[nik1981]

PP5v_S5 = 5.0v
PP3v3_S5 = 3.32v
PP3v3_SUS = 3.3v

PP3v3_S4 is boosting to 3.37v every 4 seconds

 

[nik1981]

SMC_PM_G2_EN = 3.29v

 

[nik1981]

PPVCORE_SUS_PCH = 1.001v
PPVCORE_S0_CPU_PH1 & PH2 0.00v
PM_SLP_S4_L = 3.35v pulses every 4 seconds

 

[2informaticos]

Check if PM_SLP_S3_L pulses too.
Then check if all voltages controlled by these signals also pulse.
ALL_SYS_PWRGD is pulsing?

 

[nik1981]

Okay, I’ll check that tomorrow. 11 hours until work as there’s a time difference unfortunately

 

[nik1981]

PM_SLP_S3_L and ALL_SYS_PWRGD are also pulsing

 

[nik1981]

Followed PM_SLP_S3_L into U8170, PP1v8_S3 going into U8170 is also pulsing

 

[2informaticos]

Check if ALL S3 and S0 voltages try to appear.

 

[nik1981]

So far nothing on S0

 

[nik1981]

My bad.. was on the wrong component.. PP5v_S0 is pulsing.. checking the rest

 

[nik1981]

So I get pulsing on all of these: PP5v_S0, PP3v3_S0, PP1V5_S0

Anything I've missed?

 

[2informaticos]

You should have more S0 voltages.
Not always marked as S0, but check every secondary supply enabled by PM_SLP_S3_L, or a derivate of it.
Can you see any pulse on CPU VCORE?

 

[nik1981]

Theres no pulse on VCORE

 

[nik1981]

On U8230 I had a constant 5v out for PP5v_S0 for a minute until I moved the board to recheck the first place that I checked PP5v_S0. I'm now back to pulsing though

 

[2informaticos]

Do you note any sign of liquid on the LCD connector?

 

[nik1981]

U8220 - PP3v3_sus out is 3.3v constant
U8230 - PP5v_S0 is pulsing
U8200 - PP3v3_S4 is pulsing
U8210 - PP3v3_s0 is pulsing
U8250 - PP1v8_s3 is pulsing
U8240 - PP1v2_s0sw is pulsing
U8270 - PP1v_s3 / sus is 1v constant
U8206 - PP1v_s0sw 1v constant

Are these what you mean?

 

[nik1981]

There's nothing on there under a microscope. The trackpad looks like it may have seen a touch of liquid at one edge but nothing major

 

[nik1981]

PM_SLP_S5_L is pulsing also

 

[nik1981]

PM_DSW_PWRGD is constant
CPU_VCCST_PWRGD is pulsing
ALL_SYS_PWRGD is pulsing
SMC_PM_G2_EN is constant 3.3v

So maybe U7800 issue?