820-4924 no power, PP5V_S3RS0_ALSCAM_F missing

[omiran]

Please help, Client said he shutdown night before, the next morning, the system refused to power on. Have tried all key sequences from SMC to NVRAM, no power still.

here is what I found on the Logic board.


After cleaning with isopropyl, I arrive at this:


After reading arrowed components I got 0V, but with a working logic board I got 5.1V
Apologies to my word arrangement.

 

[2informaticos]

First of all, welcome to the forum!

Marked component is L4010.
You can replace it with a tiny wire.
However, needs to have 5V on its pad 1; check that.
And be sure no short to ground at pad 2; w/ and w/o webcam connected.

 

[omiran]

First of all, welcome to the forum!

Marked component is L4010.
You can replace it with a tiny wire.
However, needs to have 5V on its pad 1; check that.
And be sure no short to ground at pad 2; w/ and w/o webcam connected.

Unfortunately, L4010 pad 1 and pad 2 read 0V
L4013 pad 1 reads 0V
L4011 pad 2 reads 0V, pad 1 reads 5.1V

 

[omiran]

Unfortunately, L4010 pad 1 and pad 2 read 0V
L4013 pad 1 reads 0V
L4011 pad 2 reads 0V, pad 1 reads 5.1V

I'm here with a positive mindset that I will get this logic board fixed. Please help

 

[2informaticos]

Ooops, I just realized your machine doesn't power at all.
I was thinking board works, but no webcam; as you specified that voltage missing.
You are missing lot of voltages probably, but didn't post accurate info...

"L4011 pad 2 reads 0V, pad 1 reads 5.1V"
Means 5V_S3 is present.

"L4010 pad 1 and pad 2 read 0V"
Means no 5V_S0 present.

Post exact voltage on PPBUS_G3H (charger only) and the big coils from the board.

Please do not use "Reply" button.
Just write in the reply box; no need to quote an entire post visible few centimeters above...

 

[omiran]

PPBUS_G3H reads 12.56V.
PP5V_S3 is present
PP5V_S0 not present.

could this break have an effect on the coil?

 

[2informaticos]

Likely not if the core is good.

"PP5V_S3 is present
PP5V_S0 not present."
I already knew that, above mentioned; expected to get other information.

"Post exact voltage on ... the big coils from the board"
???

 

[omiran]

Apologies for the delay in response, was at the wheel.

below are the readings for both big and small coil.

• L3095 - 0V
• L7130 - 12.54V
• L7195 - 5.48V
• L7560 - 3.32V
• L7710 - 0V
• L7720 - 0V
• L7430 - 1.17V
• L7820 - 1.76V
• L8300 - 0V
• L7320 - 0V
• L7310 - 0V
• L7630 - 0V

Big thanks for your help so far

 

[omiran]

I think we are getting close to a solution...

 

[2informaticos]

I bet you have 5V at L7520; do NOT forget it next time.

Post PM_SLP_S3_L signal voltage.

 

[omiran]

Noted Boss.

I will do that as soon as possible in the morning. It’s 10:43pm GMT.

Have a good one.

 

[omiran]

L7520 you're right.
PM_SLP_S3_L reads 3.32V

 

[2informaticos]

Is that steady voltage?
No higher pulse in the first second?

 

[omiran]

there was. about 5.8V max.
Ranges from 2.02V to 5.8V before it now settled at 3.32V

 

[2informaticos]

Then you must get all S0 voltages, check that now.
ALL_SYS_PWRGD goes high?

 

[omiran]

ALL_SYS_PWRGD reads 0V
S0 reads.

please what next?

 

[2informaticos]

"S0 reads."
What this mean???

 

[omiran]

S0 reads 0V I meant

 

[2informaticos]

So you don't get any S0 voltage???
It should, if PM_SLP_S3_L stays high...

 

[omiran]

Unfortunately no, PM_SLP_S3_L on R8178 pin 2 reads 3.32V
PP5V_S0 reads 0V