MacBook Air 820-00165 shutting down when trying to boot

[ACS-Repair]

Re: MacBook Air 820-00165 shutting down when trying to boot

I did this trick on an 820-00165 that I've been trying to repair for some time. On mine the computer would start up and runs for a couple of minutes, then shuts down. When I heated the capacitor it kept running, which applied more heat and the computer would continue to run until I shut it down. I've replaced C1060 and started the computer 5 or 6 times from cold and it hasn't failed yet. I need to run it for about a week to be sure.
You can expand the area and heat small areas and then test to see if at some point it makes a change the start up. I found a rare problem with the 2011 Mac Mini by doing this. I suspect that you may also have a capacitor issue and this could help you find it. It looks like you have tried everything else.

[Simplebeans]

Re: MacBook Air 820-00165 shutting down when trying to boot

Check for short on C5125, if not could be bad sensors

So I just tested C5125 and it showing a short on PIN 2 and on PIN 1 when putting my multi meter into resistance mode (200kΩ - black probe to ground point and red probe on PIN 1) its giving a reading of 143kΩ. Is that ok? Any other ideas?

[Simplebeans]

Re: MacBook Air 820-00165 shutting down when trying to boot

I did this trick on an 820-00165 that I've been trying to repair for some time. On mine the computer would start up and runs for a couple of minutes, then shuts down. When I heated the capacitor it kept running, which applied more heat and the computer would continue to run until I shut it down. I've replaced C1060 and started the computer 5 or 6 times from cold and it hasn't failed yet. I need to run it for about a week to be sure.
You can expand the area and heat small areas and then test to see if at some point it makes a change the start up. I found a rare problem with the 2011 Mac Mini by doing this. I suspect that you may also have a capacitor issue and this could help you find it. It looks like you have tried everything else.

I can for sure try this. What's the intended effect if I do this on the capacitors?

C1060 is in the 'CPU VDDQ DECOUPLING' circuit so when you say expand the area and heat small areas, any particular capacitors/areas of the board I should try?

[ACS-Repair]

Re: MacBook Air 820-00165 shutting down when trying to boot

If heating a section of the board allows the computer to fully boot it will tell you that you have a capacitor in that area that is causing your problem. Unfortunately there is no quick fix for something like this. I've been working on this problem for about a year now. It took me 18 months to resolve the Mac mini problem. Sometimes it takes a long time and some thinking outside the box. Give this a try and see if it makes a difference.

[Simplebeans]

Re: MacBook Air 820-00165 shutting down when trying to boot

If heating a section of the board allows the computer to fully boot it will tell you that you have a capacitor in that area that is causing your problem. Unfortunately there is no quick fix for something like this. I've been working on this problem for about a year now. It took me 18 months to resolve the Mac mini problem. Sometimes it takes a long time and some thinking outside the box. Give this a try and see if it makes a difference.

I will try this so any specific ones I should try this on? Previously I have tested the decoupling capacitors connected to the CPU for shorts. And to help the MacBook Air boot up what is the effect of heating the capacitors up?

When you replaced the C1060 I am guessing you didn’t find any faults when you checked it for a short?

[ACS-Repair]

Re: MacBook Air 820-00165 shutting down when trying to boot

Heating a capacitor will temporarily change its value /ESR giving it just the edge to work in circuit. It's not a fix, but it can point you to an area that otherwise tests OK. There were no shorts on the board and the voltages were all at the proper levels. These faults are difficult to diagnose because the board appears to be good but will not start or keep running.

[Simplebeans]

Re: MacBook Air 820-00165 shutting down when trying to boot

Heating a capacitor will temporarily change its value /ESR giving it just the edge to work in circuit. It's not a fix, but it can point you to an area that otherwise tests OK. There were no shorts on the board and the voltages were all at the proper levels. These faults are difficult to diagnose because the board appears to be good but will not start or keep running.

Thanks and I will try this at once, should I just go for closely connected CPU/PCH capacitors or any? This ESR value is very interesting, is there anyway to do an ESR test on the capacitors without having to remove them?

[Simplebeans]

Re: MacBook Air 820-00165 shutting down when trying to boot

So far the heating the capacitors doesnt seem to working ACS-Repair.

I have been doing some more investigation and i have found something else on the Left I/O (LIO J9500) Connector, there is a PIN missing (i think its PIN 25 - HDA_RST_L) Also the metal part that runs accross at both ends of the connector have both broken off. I have labelled it with a screenshot to make it easier to understand of what the connector looks like, please see screenshot - https://drive.google.com/file/d/16gl...ew?usp=sharing. Any ideas if these issues could be causing the macbook air to keep switching off?

I am thinking not because HDA_RST_L seems to be related to audio? Both the left and right speakers are working fine (hear the first chime) but when i plug headphones in the first chime plays out the speakers also and no sound through the headphones. And also the broken metal parts that run accross dont actually make any connection on the I/O Board Cable.

[ACS-Repair]

Re: MacBook Air 820-00165 shutting down when trying to boot

Unfortunately, I have my crashing back so it looks like that wasn't the issue. It may not be a capacitor after all although they do account for many of the problems.
I don't think the missing metal pieces are going to be a problem. The clamps at the side should hold the rest of it together. The burnt pin is going to be an issue and may have damaged the bridge cable as well. You'll need to take a look at that, and possibly replace that connector.

[Simplebeans]

Re: MacBook Air 820-00165 shutting down when trying to boot

Unfortunately, I have my crashing back so it looks like that wasn't the issue. It may not be a capacitor after all although they do account for many of the problems.
I don't think the missing metal pieces are going to be a problem. The clamps at the side should hold the rest of it together. The burnt pin is going to be an issue and may have damaged the bridge cable as well. You'll need to take a look at that, and possibly replace that connector.

Thats not good to hear i did try the heating up but none of that worked for me. I have been thinking more on this, i noticed the 5.0V rail is measuring on my logic board as 5.10V (measured at coil L7520). Is that a concern as it seems to be higher then what the rail should be producing (5V), am i right or wrong on this or does that happen sometimes? I know my multimeter is fine as per my other measurements on the other rails are all fine.

I wondered if you could measure something on your board for me, if you can measure/provide me the resistance readings you get for R5546, R5547, R7520. R7521, R7556 and R7547. I seem to be getting diffeent readings to what is on the schematic for these resisters, i am measuring them not removed from the board however but with all power disconnected. I am inbetween checking U7501 and U5540 (CPU VCore Load Side Current Sense).

Because I noticed that on U5800(CPU Proximity, Inlet ,DDR and BMON THR Sensor) on PIN 9 the CPUBMONSNS_ALERT_L and PIN 10 the PUTHMSNS_ALERT_L are both sending signals out so there is a problem with CPU temperatures? So i am thinking voltages/sensor issues.

[ACS-Repair]

Re: MacBook Air 820-00165 shutting down when trying to boot

I don't have a spare 820-00165 board so I measured on an 820-3437 in circuit.My 820-00165 is testing for crash after replacing the ISL 6259.

R5546 = 3.6k (1M)
R5547 = 1M (1M)
R7520 = 40k (41.2k)
R7521 = 9k (10k)
R7556 = 1k (4.2k)
R7547 = 1k (4.22k)

These are all measuring fairly high so if your readings are similar, it probably not the issue.

[Simplebeans]

Re: MacBook Air 820-00165 shutting down when trying to boot

I don't have a spare 820-00165 board so I measured on an 820-3437 in circuit.My 820-00165 is testing for crash after replacing the ISL 6259.

R5546 = 3.6k (1M)
R5547 = 1M (1M)
R7520 = 40k (41.2k)
R7521 = 9k (10k)
R7556 = 1k (4.2k)
R7547 = 1k (4.22k)

These are all measuring fairly high so if your readings are similar, it probably not the issue.

Thank you. I have just measured the same components in circuit on my 820-00165 board and this is the readings i got:

R5546: 3.64K (1M)
R5547: 630K (1M)
R7520: 31K (41.2k)
R7521: 9.5K (10k)
R7556: 1K (4.2k)
R7547 1K (4.22k)

The R5547 and R7520 are throwing me a little because the readings i got are not close to yours, that could be becuase they are in circuit but I will need to do some more investigation on that one.

And I wondered if you could also measure the below capicitors for me and supply me with the resistance to ground readings:

C2740 (630 Ω)
C7648 (217Ω)
C1910 (7MΩ)
C6100 (54kΩ)
C1031 (14-18Ω)

So thats interesting what was the thinking behind the ISL chip? How come you made a move on that?

[ACS-Repair]

Re: MacBook Air 820-00165 shutting down when trying to boot

This is what I got for resistance:

C2740 = 664Ω
C7648 = 199Ω
C1910 = 10MΩ
C6100 = 17.5KΩ
C1031 = 144Ω *

I don't think the resistor measurements are that far out of line given the two you mention are pretty high. The measurements on the capacitors are also very close except for C1031. That capacitor is across your CPU, and that resistance is going to be different between the CPUs of 2013 and 2015. I checked the Wiki to confirm the CPU resistance for your model and it should be 15Ω.

I would think the resistance on C6100 should be closer. make sure that your meter polarity is correct on that one. It's probably better to confirm that you have the correct voltage for PPV3V3_SUS on that capacitor.

[Simplebeans]

Re: MacBook Air 820-00165 shutting down when trying to boot

This is what I got for resistance:

C2740 = 664Ω
C7648 = 199Ω
C1910 = 10MΩ
C6100 = 17.5KΩ
C1031 = 144Ω *

I don't think the resistor measurements are that far out of line given the two you mention are pretty high. The measurements on the capacitors are also very close except for C1031. That capacitor is across your CPU, and that resistance is going to be different between the CPUs of 2013 and 2015. I checked the Wiki to confirm the CPU resistance for your model and it should be 15Ω.

I would think the resistance on C6100 should be closer. make sure that your meter polarity is correct on that one. It's probably better to confirm that you have the correct voltage for PPV3V3_SUS on that capacitor.

Hey ACS-Repair the values i provided in my past post was from the Wiki page aswell (https://logi.wiki/index.php/Resistance_to_Ground_List), the below values are my actual readings from the capactiors on my board (Meter in resistance mode, black probe to ground point and red probe at the capacitor, no battery or charger connected):

C2740 = 504Ω
C7648 = 302Ω
C1910 = 0.86MΩ
C6100 = 74KΩ
C1031 = 14.5Ω

The one that was concerning me was C1910 this seems really low. Any thoughts on this? It seems its part of the U1900 - System RTC Power Source & 32kHz / 25MHz Clock Generator. This is a post i found when searching online - https://boards.rossmanngroup.com/thr...low-1-3v.8279/. I really hope i am wrong and its just a shorted capacitor or U1900 chip. Factor in the CPU/PCH getting hot as mentioned in my first post on this thread, does it seen likely?

I am however getting a reading of 3.3V at pin 1 on U1900 chip. Bearing in mind my board does power on, get to post and shuts off on the apple logo screen about when it reaches just above halfway through the progress bar.

[mon2]

Re: MacBook Air 820-00165 shutting down when trying to boot

C1910 = 0.86MΩ

0.86Mega ohms = 860k ohms = 860,000 ohms. It is fine and not a low resistance.

C1031 = 14.5Ω

This is low but ok if on a low voltage rail.

[Simplebeans]

Re: MacBook Air 820-00165 shutting down when trying to boot

0.86Mega ohms = 860k ohms = 860,000 ohms. It is fine and not a low resistance.


This is low but ok if on a low voltage rail.

Thanks mon2.

C1031 is the capacitor accross the CPU circuit so i would have thought that my reading would be ok on that yes, according to https://logi.wiki/index.php/Resistance_to_Ground_List under the 'CPU resistance > Broadwell' section it says it should be around 18Ω.

About my C1910 reading I was compiling my logic made from the comments made here - https://boards.rossmanngroup.com/thr...low-1-3v.8279/ that it should be well over 1MΩ and the wiki page also says - C1910 PPVRTC_G3H ~ 7 MΩ.

[Simplebeans]

Re: MacBook Air 820-00165 shutting down when trying to boot

To add to my previous information i just tested the capacitors (Meter in diode mode black probe to ground and red probe at PIN 1) C0892, C0891 and C0890 all at PIN 1 and the resistance is values keep jumping around and don't seem to stabalise. C1300 and C1303 are also behaving the same and I have not seen this when testing any other capacitors previosly on the board. Could this be anything?

[Simplebeans]

Re: MacBook Air 820-00165 shutting down when trying to boot

I was checking out the CPU/PCH today and found this on the CPU (bottom left hand side), does anyone think this scratch/anomaly could be causing the shut downs? See link below for the image.

https://drive.google.com/file/d/159W...ew?usp=sharing

[Simplebeans]

Re: MacBook Air 820-00165 shutting down when trying to boot

Hey ACS-Repair so guess what i FIXED IT!, haha what a result. So I ordered a EFI chip a couple of days ago and low and behold after replacing- it worked. No more shut downs and now i get the boot chime and it gets to the flashing quesiton mark folder.

Thanks to the others that chimed in mon2, reformatt and bluestone.

Admins can you please mark this one as solved so that others can have a go if they experiencing the same issues.

I hope the SSD is ok as ordered this one in from ebay a few weeks back. I am still thinking on replacing the Left I/O (LIO J9500) Connector because of that blown PIN as well.

Now i need to work out this flashing question mark folder i have tried all the key combinations and i just cannot get it to boot into any sort of recovery mode. I hope the SSD is ok as ordered this one in from ebay a few weeks back.

[mon2]

Re: MacBook Air 820-00165 shutting down when trying to boot

@Simplebeans - well done!