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Anterweb

Anterweb

Member
I thought this would be an easy one, but alas!

Boots and runs great but it keeps going into what looks like sleep mode,
screen goes black and keyboard lights go off,, It instantly wakes fine the second you touch a key or the trackpad.
It seems to happen a lot but still randomly. and its bad enough to make the Mac unusable.

tried all power sleep options,

It was running El Capitan , tried formatting the drive and installing High Sierra still the same issue.,

Have tried Pram and SMC reset, no change.

This has to be a hardware issue right?
any help much appreciated
 
2informaticos

2informaticos

Administrator
Staff member
Check SMC_LID behavior; it must be steady 3.3V.
Inspect J9500 solders.
Also test known good LIO board/flex.

BTW, use ORIGINAL Magsafe 2 charger.
 
Anterweb

Anterweb

Member
2informaticos said:
BTW, use ORIGINAL Magsafe 2 charger.
Click to expand...
. :D Oh fuck dude this made me laugh! and it's the first time I have smiled today and it's my Birthday! (had a proper shit day! )


I just gave j9500 a good look over in the scope, noticed a little bit of crap inside the connector, give it all a proper clean and now it looks like new, changed the LIO board/flex for a known working one problem still there,


Weirdly I tried booting the Mac with the LIO board/flex removed and it works fine, No more screen off or going into sleep mode,.
But fans run high and it's a bit glitchy with it removed,

Is this small board the flex connects to repairable or do I just replace it?
 
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Anterweb

Anterweb

Member
Dude just about to check this but, should it be done with just logic on the bench or does it need to be done with evything in the mac connected and the screen on?
 
Anterweb

Anterweb

Member
Solid 3v on all SMC_LID locations , Left the multimeter on these spots for 5 mins at a time no drops at all

Tested lid sensor with magnet and voltage drops to almost 0 when magnet close then back to 3v when move magnet away,
Put it back together boot into OS and with 45 seconds ish, Screen goes black and keyboard lights off have to push key or touchpad to awake,,,

This is bizare!
 
Anterweb

Anterweb

Member
SO just pulled a LIO board ( DC power, sister board?) out of another a1466 Problem gone!

But only the left speaker is working :oops:

It's not software related,

Just tried the known good one from the donor machine, same deal no right speaker, could this be related to that LIO board?
 
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Anterweb

Anterweb

Member
Just tried popping the old LIO board in, sleep problem come streight back, but also no right speaker, so this must have been happening before and I never noticed as I wasn't looking for it. Anything common to look for with a right speaker not working?

Ive tried reset smc , pram,

Tried plugging in headphones, They work fine,

Multimeter shows 2.6v on the clip for plugging in the left speaker but just Mh on the same spot of right speaker, (j6404)
 
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Anterweb

Anterweb

Member
Just watching this Paul Daniels vid on an audio problem with the a466
And the audio chip is on the dc in board,,
I can't find any schematic for this board, but as the right speaker isn't working with 2 different dc in boards and 2 different LIO flex cables im wondering if its LIO port problem or trace problem on the MLB, is there a way of running a jumper from the dc in board to the MLB to text this do you think?
 
2informaticos

2informaticos

Administrator
Staff member
Right audio amplifier is on MLB.
Only audio codec and left amplifier are placed on LIO board.

Check U6410 PVDD and SHDN*.
 
Anterweb

Anterweb

Member
All 9 pins of U6410 as follows

pin 1 = 5v
pin 2 = grnd
pin 3 = 0.5mv
pin 4 = 1.1mv
pin 5 = gnd
pin 6 = 0.3 mv
pin 7 = 1.1 mv
pin 8 = 0.3 mv
pin 9 = 25.3 mv
 
2informaticos

2informaticos

Administrator
Staff member
You have one board on the work; no need to open more than one boardview.
I usually have 20 schematics opened in Acrobat Reader, for online assistance; should I also open boardview for each one???
PLEASE, use schematic when you refer chip pins; or use signal NAMES.

You have a problem with U6410 SHDN* (SPKRAMP_SHDN_L) signal.
It comes from pin 29/J9500; check the solder.
 
Anterweb

Anterweb

Member
Sorry about the pin board view mix up,

Looks like the j9500 connector maybe at fault here, is it easy enough to replace it with one from a donor board (I've never done this before)?

Or would it be easier to run a jumper from the same pin on dc in board to the same pin on the mlb?
 
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