820-00164 green Magsafe LED, no fan spin

[Pedro147]

820-00164 / A1465 no evidence of liquid damage, overall a clean looking board.
Green Magsafe LED on plugin changing to orange shortly after but no fan spin.Now I believe that this board should have fan spin when only plugged into charger with no battery, well if it wasn't broken that is

• PPDCIN_G3H 15.1v
  
• PP3V42_G3H 3.42v
  
• PPBUS_G3H 8.61v
  
• PPVRTC_G3H pulsing 3.32 - 3.45v (only measured with multimeter not scope) DM (Diode Mode) 0.403v
  
• PP3V3_S5 (DM 0.327v) and P3V3S5_EN_R (DM 0.455v) both fluctuating from 0 - 3.3v
  
• PP5V_S5 0 - 5v fluctuating (DM 0.448v)
  
• no SMC_PM_G2_EN at U7501

I understand that U7501 is responsible for creating both the PP3V3_S5 and PP5V_S5 rails but since they are fluctuating I am led to believe that this could be because of a bad SMC, a short on one or more of these rails or a bad U7501. I have no real idea on how to move forward and would appreciate any suggestions please.

[piernov]

Re: 820-00164 green Magsafe LED, no fan spin

P3V3S5_EN_R comes from SMC_PM_G2_EN so I guess it's pulsing as well. This could indeed be caused by a bad SMC, a bad U7501 or a short on one of its output. Assuming PP3V3_S5 and PP5V_S5 are good for now, monitor the voltage on PP5V_S4RS3, and measure resistance to ground on this rail.

[Pedro147]

Re: 820-00164 green Magsafe LED, no fan spin

PP5V_S4RS3 is fluctuating as well and diode mode is 0.411v. I tried to get a resistance to GND but it was changing anywhere from 17 - 138K as best as I could tell. Isn't that why diode mode is better, quicker and more stable.

Doesn't that about cover all the rails being produced by U7501, and are the diode mode readings indicating no shorts? Assuming that the SMC either reball or replace is the more diifult to do, might I be better to replace U7501 with one I have from a donor or is there something else that I can test please.

[piernov]

Re: 820-00164 green Magsafe LED, no fan spin

There are power rails derived from PP3V3_S5 and PP5V_S4RS3, so it'd be a good idea to check them as well (voltage + resistance to ground), one could be shorted to ground.

[Pedro147]

Re: 820-00164 green Magsafe LED, no fan spin

Thanks I'll look at power aliases I assume and see what I can find. I should of thought of that

[Pedro147]

Re: 820-00164 green Magsafe LED, no fan spin

@piernov I had a look at Power Aliases for this 00164 but I cannot work out how to find the rails which derive from PP3V3_S5 and PP5V_S4RS3. Any clues please ?

[Pedro147]

Re: 820-00164 green Magsafe LED, no fan spin

Sorry about all the posts but the edit option disappears after some time for some strange reason.
Well I found some corrosion on R7520/21 (P5V_S4RS3) so I cleaned the area up and replaced them from a donor.
Now I have steady readings on these rails that were pulsing before -

• PP3V3_S5 (3.348v)
• P3V3S5_EN_R (3.429v)
• PPVRTC_G3H (3.347v)
• PP5V_S5 (5.03v)
• SMC_PM_G2_EN (3.347v)

So that leaves PP5V_S4RS3 still pulsing diode mode 0.400v. Any idea where I should go now please

[Pedro147]

Re: 820-00164 green Magsafe LED, no fan spin

I seem to be talking to myself here but regardless I got fan spin and it booted to the lock screen. It was too late to get the password from the guy I bought this non functional machine from so I tried to get into the terminal to resetpassword. I also tried internet recovery but the progress bar hangs up trying either method so I am stuck. Always something

[SMDFlea]

Re: 820-00164 green Magsafe LED, no fan spin

I seem to be talking to myself here but regardless I got fan spin and it booted to the lock screen. It was too late to get the password from the guy I bought this non functional machine from so I tried to get into the terminal to resetpassword. I also tried internet recovery but the progress bar hangs up trying either method so I am stuck. Always something

@piernov is the only one around this forum at the moment replying to any macbook issues. He cannot be here 24/7 .If you have a password issue please post the bios backup in the "Bios Requests" section ,someone will remove the pass for you, if you`re patient .

[Pedro147]

Re: 820-00164 green Magsafe LED, no fan spin

II was only trying to be funny but my poor attempt at humour was obviously misconstrued, I apologise

I know that Piernov is run off his feet helping many people everyday on a number of platforms. His help is greatly appreciated as is help freely given by quite a few in the various communities

As for "If you have a password issue please post the bios backup in the "Bios Requests" section ,someone will remove the pass for you" I really have no experience with that at all so I will have to try and find out about it. Thanks for your reply