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Anterweb

Anterweb

Member
Came in today for "wont turn on"

Tried iit nothing happens,. Open back and battery looks swollen., remove battery and pop in new one,. Works perfectly, but slow due to 2gb ram only,. so I upgrade the RAM.

Boots fine runs fine but I notice Pink tinting to screen and slight graphics glitches souse Medusa to to kill AMD and remove R8911. Machine boots fine and only showinng Intel chip. I update OS and check battery is charging ok all is good so shut it down,.

Come back to it today to test before giving it back and It wont power on. All I get is a quater fan spin endless loop.,

Ive tried evreything I can still no dice,

Board alone on the desk nothing connected just the original 2gb ram I get constant quater fan spin loop and following Big coil voltages,


L7220 - Pulses on fan spin
L7260 - Solid 3.33v
L7550,L7510,L7520,L7530 all 0v
L7030 Solid 12.55v
l7630 Pulses
L9510 - 0v
L7330 Pulses

Any ideas dude?
 
2informaticos

2informaticos

Administrator
Staff member
Did you try SMC bypass mode?
Be sure to use original 85W Magsafe 1 charger.

Be aware of PRAM reset; in such case, need to reflash BIOS with Medusa, to disable GPU again.
 
Anterweb

Anterweb

Member
Smc bypass gives full fan spin but no boot.
I only use original 85 watt on the bench since my previous fuck ups.

Concerned about pram I've reset and even reflashed the bios with 2 known good bios files, and disabled gpu with medusa same outcome
 
2informaticos

2informaticos

Administrator
Staff member
"Smc bypass gives full fan spin but no boot."
Do you mean the board stays on, but no activity.
In such case, there is a problem with some SMC sensor (current, or voltage); check pages 48 & 49.
Once find that, maybe get activity too.
 
Anterweb

Anterweb

Member
In SMC Bypass I get high fan spin that stays on but no chime , no screen on and no activity.

Whats the best way to check and measure these dude, Should I go through each of these sensors checking for voltage going in and back out or should I be checking all the resistors to see if the values match the schematic or both?
 
Last edited:
Anterweb

Anterweb

Member
Gave this a go tonight, New territory for me but eager to understand this and get it down,.

Started to feel a little lost when getting so many 0v readings,

Doing this with board alone on desk and magsafe connected so getting constant quater fan spin as I measure,


c5304 -2.08v
c5308 - 0v
c5314 - 2.7v
c5327 - 0v
c5320 - 0v
c5267 - 0v
c5377 - 0v
c5403 - 1.8v
c5451 - 0v
c5413 -1.8v
c5435 - 1.8v
c5422 - 0v
c5461 - 0v

This mean anything to you, I'm guessing a Vcore sensor looking at the svchem?
 
Anterweb

Anterweb

Member
In SMC bypass I get .

c5304 -2.2v
c5308 - 0v
c5314 - 2.88v
c5327 - 4.1MV
c5320 - 0v
c5267 - .669v
c5377 - 0v
c5330 - .5MV
c5335 - .8MV
c5403 - .325v
c5451 - 0v
c5433 -.397v
c5422 - .289v
c5461 - 0v

Not really sure what to do with this, Was hoping to find them all giving out a noticeable voltage accept for one that was bad?
 
2informaticos

2informaticos

Administrator
Staff member
" c5327 - 4.1MV"
What this means?
I doubt you gan get Megavolt there!
So, is that 4.1V, or 4.1mV (milivolt)???

4.1V is far to high.
If is the case, check R5323/24 and their traces to R7640.
 
Anterweb

Anterweb

Member
Pmsl.
Sorry dude
Just got back from a long day in the cold visiting santa with my lunatic kid!

MV = milivolt
 
Anterweb

Anterweb

Member
Understood.

Looks like these sensor readings are pretty much the same as when not in smc bypass.

This one for the scrap pile or anything else I can try?
 
2informaticos

2informaticos

Administrator
Staff member
"So, is that 4.1V, or 4.1mV (milivolt)???

4.1V is far to high.
If is the case, check R5323/24 and their traces to R7640."
???
 
Anterweb

Anterweb

Member
Still quarter fan spin is remove the RAM module? Yes was one of the first things I tried, no ram and different Ram modules,

Is AVREF_SMC present? Yes 3.28v
 
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