Apple Macbook Pro 820-2936 no image

[experience2080]

Hi all,

my macbook just died. I get the chime, backlight but no picture, nothing on the external display.. no dvd drive noise, no hard disk access

USB has power, cpu-vcore is ok about 0.86V, lvcds lines are ok, L9080 is ok.

Could the PCH be dead?

thanks for any info..

[mon2]

Re: Apple Macbook Pro 820-2936 no image

Try a PRAM reset.

https://www.macworld.com/article/224...m-and-smc.html

[experience2080]

Re: Apple Macbook Pro 820-2936 no image

Already tried that, smc reset too, makes no difference. i think the keyboard is not working either, caps-lock is not working and no light..

[mon2]

Re: Apple Macbook Pro 820-2936 no image

Check and post the following voltage rails:

1) PP1V05_S0

2) PP3V3_S0

3) PP1V8_S0

4) PP5V_S0

5) PP5V_S0_PCH_V5REF

6) PP3V3_SUS

7) PP3V3_S0_PCH_VCC3_3_CLK_F

8) PP1V05_S0_PCH_VCCADPLLA

9) PP1V05_S0_PCH_VCCADPLLB

10) PP1V05_S0_PCH_VCCADPLL

The above are rails as seen on sheet 20/86 that power the PCH.

What is the history of this macbook? Just decided to not work or any known liquid damage ?

[experience2080]

Re: Apple Macbook Pro 820-2936 no image

Thanks, i will check the rails. Give me 1-2 days.

No real history available i am afraid. No signs of liquid damage, but i used a 3rd party charger that broke about 2-3cm at the end where the magsafe connector is. maybe short circuit? i repaired the charger, it works fine now. green light is there and the battery charges fine.

Looks like everything coming from the PCH is dead. No keyboard, no dvd drive noises, no hard disc access and no picture internal or external. Strange..

Anyway thanks for now, i will post later the rails.

[experience2080]

Re: Apple Macbook Pro 820-2936 no image

Here are the rails:


1) PP1V05_S0 --> 1.056 V

2) PP3V3_S0 --> 3.295 V

3) PP1V8_S0 --> 1.82 V

4) PP5V_S0 --> 5.00 V

5) PP5V_S0_PCH_V5REF --> 4.96 V

6) PP3V3_SUS --> 3.312 V

7) PP3V3_S0_PCH_VCC3_3_CLK_F --> 3.195 V

8) PP1V05_S0_PCH_VCCADPLLA --> 1.058 V

9) PP1V05_S0_PCH_VCCADPLLB --> 1.057 V

10) PP1V05_S0_PCH_VCCADPLL --> 1.059 V

PCH gets warm, not hot just warm. Broken EFI Bios chip maybe?