Re: Macbook Air 820-3437 - Random Re-boots
For anyone looking for a solution to a similar problem, this ended up being solved by the ultrasonic cleaner. I'm assuming it was corrosion under the SMC as suggested on another forum.
fred23456
Member
Last Activity: 11-27-2019, 02:06 PM
Joined: 04-23-2019
Location: Little Compton
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Re: Macbook Pro 820-3662 No Chime, No Display
85W charger arrived, the problem persists, light on the charger, fans spin but no display and no chime. CPU Vcore is still at 1.7ishV.
I've tested all 5v, 3v and 1v rails listed under power aliases and all are present.Leave a comment:
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Re: Macbook Air 820-3437 - Random Re-boots
I haven't got another SSD unfortunately. Just tested it using ASD on a USB stick, selected all tests and let it run, it rebooted during that as well, twice in a row.
The EFI is untouched and I just tried running memtest, computer shuts down before it has time to finish!Leave a comment:
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Macbook Air 820-3437 - Random Re-boots
Hi all,
Got a Macbook Air 820-3437. Had liquid damage and has had quite a lot of repair work done on it to get it where it is now.
It now passes everything in ASD and boots to the OS, all be it a little slowly, the loading bar on boot takes a few seconds and usually stalls at about 60%. Once in the OS everything is normal, computer runs as fast as ever and CPU idles at around 40 degrees C.
After about 20-30 minutes the computer will turn off and immediately restart. Sometimes the "your computer turned off because of an issue" message pops... -
Re: Macbook Air 820-3437 - Fan 100% and Magic Mouse Screen on Boot
Ran the jumper loosely round the board to test and the fan spin is back to normal! Going to get some solder mask to make sure it's insulated and doesn't cause any other issues. It's a bit of a journey it has to take round the board! I'll give ASD another run and check whether the sensor passes once I've got the wire routed properly.
Cannot thank you enough for your help! You've helped save my computer from what I thought was certain death.
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Tested with ASD after routing...Leave a comment:
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Re: Macbook Air 820-3437 - Fan 100% and Magic Mouse Screen on Boot
I did indeed continue on error in ASD. The touchpad is definitely the only sensor that's wrong.
I have 3.3 volts on SMBUS at U5810 on pins 9 and 10 and on R5390 and R5391. Pin 16 (SMBUS_SMC_3_SDA) of the connector is also 3.3V but pin 17 (SMBUS_SMC_3_SCL) is 0.4V
I can't get continuity on SCL to U5810. Easily get it resting the probe on U5810 pin 9 and running it across the connector but nothing on pin 10. Is it time to start running jumper wires?Leave a comment:
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Re: Macbook Air 820-3437 - Fan 100% and Magic Mouse Screen on Boot
As mentioned previously, I've switched around 2 touchpads, tried 2 new flexes and have soldered 2 new connectors onto the board and the issue remains the same whilst other problems with the keyboard/touchpad disappeared.
As far as I can tell from the schematic the data line from the touchpad connector goes straight to the SMC on this board? Would really appreciate if you could verify whether I'm right or not.Leave a comment:
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Re: Macbook Air 820-3437 - Fan 100% and Magic Mouse Screen on Boot
Hi there, sorry for the delay in responding. Managed to find and setup ASD.
Failed tests are as follows:
Ts0P Trackpad Skin - reading below the low limit.Last edited by fred23456; 05-26-2019, 02:20 PM. Reason: Re-tested with battery connected, different results.Leave a comment:
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Re: Macbook Pro 820-3662 No Chime, No Display
Thanks, my charger is 45W so that explains it!
Thanks for the help with CPU VCore, it is reading 1.76V.Leave a comment:
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Re: Macbook Pro 820-3662 No Chime, No Display
Thanks for the reply, the AC adaptor is a genuine Apple Magsafe 2, I use it on my personal laptop so I know it's good! I do get a light on the charger with just the adaptor, just no fan spin. I also get some power rails up e.g. PP5V_S5, PP3v3_S5
I've tried a PRAM reset, with no results, exactly the same.
Could you give a bit of guidance on measuring CPU VCore? Had a look on my boardview and can't find it listed on there.Leave a comment:
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Re: Macbook Air 820-3437 - Fan 100% and Magic Mouse Screen on Boot
Just an update to this, the mac now boots into the OS. I blew a little air into the keyboard/touchpad connector on the logic board and must've cleared out something. The keyboard and touchpad are working properly now.
The fan is still spinning at 100% and the computer is running a bit slower than usual.Leave a comment:
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Macbook Air 820-3437 - Fan 100% and Magic Mouse Screen on Boot
Hi there,
Working on a water damaged Macbook Air 820-3437.
The fan ramps up to 100% on boot and stays that way, I believe the sensor causing this is the touchpad palm sensor as all the others read usual values, aside from this one which reads nothing.
I checked the touchpad flex, it was corroded so I replaced it with no change in behaviour. I then removed and re-soldered the touchpad connector on the logic board (also corroded inside). This also did not fix the problem. I swapped the touchpad for a replacement and still have the issue. I've tried the unplug... -
Macbook Pro 820-3662 No Chime, No Display
Hi there,
New to component level repair so your patience would be hugely appreciated!
I'm working on a water damaged Macbook Pro 820-3662.
Firstly, I get no fan spin and no S4_PWR_EN without the battery plugged in, however this comes on with the battery and adaptor.
With battery and adaptor, it has a light on the charger and fan spin but I get no chime and no display.
EDP_IG_PANEL_PWR is currently 0V but PP5V_S4 is 5V, thats the extent of my troubleshooting for display related stuff.
The CPU gets warm so something is going... -
Re: New Members - please post your introductions here
Hi there,
I'm Fred, been learning component level repair for a few months from a position of 0 experience before that. By trade I'm an ERP system consultant. I've been working on water damaged Macbooks and now I'm hooked!
Looking for some advice from the community for a couple of Macbooks I'm really stuck with.
Hopefully I can help some of you guys out as well with areas I'm more knowledgeable in.
All the bestLeave a comment:
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