820-2879 not turning on.

[2informaticos]

Check the signals from power on sequence on battery only.

 

[BCN_Techs]

Could you detail more
what you mean please, i don?t understand that part, sorry.

 

[2informaticos]

The basic signals wich you check for a non-power issue.
3V42/PPBUS_G3H, SMC_RESET_L, RTC_RST_L, SM_INTRUDER_L, 0V9_S5...

 

[BCN_Techs]

PPBUS - 12.3 ( bad smc? i changed it twice, from donor)
PP3V42_G3H - 3.42 V
SMC_RESET_L - 3.4 V

RTC_RST_L - 3.4V
SM_INTRUDER_L - 3.4V

PP0V9_S5 this one is 0V.

So if pbus from battery on 12.3 is ok then the fail must be 0V9_S5 so i went to U7750 and see that PP3V3_S5 is not generated from battery.


Is it U7200 not recieving P3V3S5_EN from U7840 because this one doesnt get SMC_PM_G2_EN. So my fail is SMC?

 

[2informaticos]

Sorry, S5 state not achived on battery only, so no 0V9_S5 available.

12.3V on battery alone?
Did you try known good battery?

 

[BCN_Techs]

Yes, i have 2 batteries extracted from macbooks with less than 10 cycles. Just put them back to check if they work and yes one is half charged it gives (11.6V) and other have 95% and gives 12,3 V on ppbus

 

[BCN_Techs]

also i can start in smc bypass from battery ( with no magsafe) but CPU not turning hot, so seems it is just entering s0 state without booting. i think even after changed twice the SMC it is failing
or smc or something near.


What u think?


P.S. connected display and from battery i can make fan spin in smc by pass but no image not bootng.

 

[2informaticos]

If board starts with battery and charger in SMC bypass, check all voltage and current sensors in normal mode (pages 39/40).

 

[BCN_Techs]

I checked already all parts componentes, replaced SMC again and now, it works with battery and magasfe connected. But it doesnt boot if only battery, just spin hdd i can hear, for few seconds than stop.


Whe running from battery it shut down ( sometimes after 2 seconds other may delay untill 1 minute and shut down.

 

[2informaticos]

Both batteries work properly with other board?

 

[BCN_Techs]

Yes. Its very very strange problem. Today after cleaning a little board check ( visual) it booted from battery, without magsafe, after few boots it stopped working and return to previous issue

 

[BCN_Techs]

Give me any idea someone please . I need to find out what the hell is wrong with this mac.



SMC bypass with battery is booting too.

 

[2informaticos]

Does it charge the battery?
Do you get amber light when both charger and battery connected?

 

[BCN_Techs]

yes, it charge untill 100% and pass from amber to green.

 

[2informaticos]

Test the machine disconnecting internal keyboard.
Use R5014/15 pads to turn it on.

 

[BCN_Techs]

yes, R5014 was i had been using whole time but it doesnt work with only battery ( sometimes works). Without keyboard

 

[BCN_Techs]

i retake this board finally. Anyone can help me with that?

Run from charger, charge battery, but not running from battery. The only way to run from battery is to boot it in smc bypass or boot with magsafe connected and disconnect if after booting

 

[2informaticos]

We need some power sequence signals on battery only.
When doesn't start, of course.