820-00163-05 No keyboard or trackpad after no boot due to capacitor short.

Cire3

Member
MacBook A1398 board 820-00163-05

Had a short to ground on C7324 PPVIN_S5_HS_COMPUTIN and not allowing unit to boot.

Replaced the capacitor with Tantalum Polymer 16V 68uF 2917 20% ESR=50mOhms.

System boots up to desktop and I'm thinking in good to go.

Not so fast. No keyboard or trackpad. I can plug in usb, however that's it. Power button works, but SMC reset, or options on bootup seem not to function.

I do have PP3V42_G3H on pin 4 , but nothing on pin 30 PP3V3_S4

How do I follow on the schematic where it's fed from. It shows the trace from keyboard connector , stops, and a crap load of numbers ? What are these numbers next to it ?

Page 38 shows a trace, and I don't understand where from ?

Any help is much appreciated !
 

2informaticos

Administrator
Staff member
3V3_S4 comes from Q8000 (page 66).
Post Q8000/2 voltages?
Be sure no short on 3V3_S4 rail (w/ and w/o trackpad connected).
 

Cire3

Member
Thanks for the quick replay !

Ok, hair confused.

I see Q8000 as a 6 leg chip on the board. However the schematics I see it portrayed as 4 legs, 1 on top and 3 under.

So I posted what I see and tested from both views.

Q8000 Actual Photo of board has Ohms as well as voltage (Board out of the unit)

No short to ground on Q8000
 

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Cire3

Member
Oh and a follow up.

Pin 30 on keyboard connector J4813 actually does get 3.34V from Q8000. However after about 30 seconds I lose it . Board is out of unit (Breadboard). Not sure if that's normal, but didn't want to leave that info out.
 

2informaticos

Administrator
Staff member
Still waiting voltages for Q8000/2; means Q8000 AND Q8002.
Especially when 3V3_S4 goes off.

Use signal names from schematic, to locate in boardview.
 

Cire3

Member
Very sorry, was forced off the job and then the holidays.. Hoping you had a good one.

For Q8002. this is what we have.

Pins:

1 : 0.0V / 1.0 Ohms
2 : 0.0V / 8.0 Ohms
3 : 3.31V / Open
4 : 0.0V / 0.4 Ohms
5 : 0.0V / 47.6 Ohms
6 : 3.2 V / Open

Again sorry for the delay, and thanks for your time !
 

2informaticos

Administrator
Staff member
Very strange ohm values.
I hope you disconnect any power first.
Allow 10-15s and check on DIODE mode, not ohm scale.
BTW, no need to check ground pins (1 & 4)!

"5 : 0.0V"
Looks like board goes off; missing PM_SLP_SUS_L.
What about PPBUS_G3H and 3V3_S5 at same time?
 

Cire3

Member
Ok, think I had something wrong?

Ohms by Pin :

1 : 0.5
2 : 9.8 m
3 : 101.9 k
4 : 0.5
5 : 99.5 k
6 : 219.0 k

I'll check the rest of the items now.
 

Cire3

Member
Diode Mode :

2 : Open
3 : Open

5 : Tone
6 : Open


PPBUS_G3H : 12.59 ? Taken @ Q5400 Pin 4 and R7005 Should be 3V right ?

PP3V3_S5 : 3.34V
 

2informaticos

Administrator
Staff member
We ALWAYS check diode mode with red probe connected to ground.
You cannot get OL in such case.

I already said do NOT check ground pins.
What do you think to get measuring GND-GND???

Was 3V3_SUS missing?
 

Cire3

Member
Ok. I must need a few more days off...

Using Pos on ground in diode. Power Disconnected. Third times a charm

2 : 0.434 V
3 : 0.434 V
5 : 0.626 V
6 : 0.617 V


PP3V3_SUS 3.34 V
 

Cire3

Member
Is the above what we were looking for ? Newish to this, and yesterday was not a good example .....lol
 

2informaticos

Administrator
Staff member
If you have 3V3_SUS, then pin 5/Q8002 debe tener 3V al mismo tiempo.
This imply 0V at pin 3.
Remember, check mentioned signals and voltages, when the problem appears!
 
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