Hi, the owner of the a1708 got impatient and had me order a replacement board instead. I will get back to the damaged board when i have spare time to try to get it back running so I have a spare, just in case.
The boot sequence voltages I look up on openboarddata, on the home page there is a long list of macbook motherboards listed by their part numer, click on one of them and it will open a page with all known values. (known as in amongst their verified submissions)....
master_haze86
Member
Last Activity: 04-13-2026, 07:10 PM
Joined: 11-04-2023
Location: Manabi
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I just finished inspection with voltage injection of 1v on the PP3V3_G3H rail.
Stuck the k-type thermocouple of my multimeter directly to the cpu die with a bit of kapton tape and thermal paste and used ipa on the rest.
None of the capacitors heated up but during the process the cpu did go from 30°C (ambient temp) to 35°C. 🤦♂️
Sincerely,
Rick....Leave a comment:
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I do have a lab/bench power supply but unfortunately do not have a thermal camera just yet. Will have to "feel" around using my multimeter's temperature probe.
Its about 8pm here, will do this test tomorrow and post results here. Fingers crossed its not the CPU but sensing impending doom.
Sincerely,
Rick.Leave a comment:
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Hi Mon2, thank you for your reply,
Measuring resistance between the PP3V3_G3H test pad next to R6999 and the closest screw hole ground pad I get near 0 Ohm reading, definitely shorted.
(probe tip to probe tip i get a base reading of 10.8 Ohm, test pad to nearest screw ground pad I get a 12.2 Ohm reading. so test pad to ground pad resistance is 1.4 Ohm)
PP1V1_UPC_XA_LDO_BMC measures 0V no matter which of the two usb ports the charger is connected to.
Sincerely,
Rick.Leave a comment:
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no boot: macbook A1708 EMC3164 820-00840-A
Good day everyone.
I got a macbook a1708 emc 3164 in the shop with an 820-00840-A logic board that won't turn on, with nor without the battery and would greatly appreciate help in finding the fault.
Checking voltages in boot-sequence:
1) [p:F3000] 5V VBUS PRESENT @ 5V
2) [n:UPC_XA_GATE2] and [n:UPC_XA_GATE1] 7~10V GATE 1: 10V GATE 2: 7V
3) [n:PPDCIN_G3H] 5V PRESENT @5V
4) [p:R7075:1] (VDDA) to [p:R7075:2] (VDDP) and ensure R7075 is 4R7 CORRECT @ ~4.7 OHM
5) [n:PM_EN_P3V3_G3H] signal from [p:U7000] to [p:U6990:10] PRESENT @ 5V
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Thank you for the schematics. Now I just need to find the boardview somewhere.Leave a comment:
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Unfortunately my usb volt meter died on me the other day, but checking the bottom of the board (the side facing you when laptop is flipped over with the cover removed) for PP3v3_S5 I do not get a 3.3v reading, just a few milivolts.
Hope you are doing well and have fun in Asia while there. Business trip to an expo I am guessing?
Thanks for all the help so far.
Sincerely,
Rick....Leave a comment:
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So I had a lot of luck and a friend of mine for whom I have done a lot of pro-bono work reached out to me and asked if I needed any tools for my work as he had received a nice windfall and could help me out as compensation for all the work I had done without charging a penny. So I pointed out my lack of a microscope. I am pleased to say I no longer lack a microscope! I now have a mechanic robot z4. ^_^
Ok, enough with celebrating the new tool, back to work. I used the microscope to check the area around Q3100 where the corrosion was and the capacitor that got ripped off the pad. Did...Leave a comment:
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Would it be an issue to change CC772 with a 15pF 50v 5% capacitor instead of the original 12pF 25v 5%?
I would absolutely purchase a 4k model with proper c-mount optics if I could afford one, really! We've got a distributor for mechanic brand equipment here in Ecuador that has nice trinocular microscopes but they cost $300-$600 each. Just mentioning that minimum wage here is $450 and most of the time I struggle to earn even half of that each month, that should give you an insight in how high of an investment it would be for me. At best I am going to be able to afford one of these...Leave a comment:
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Haven't been wanting to, because I know they really aren't that good, but guess I will have to fork over the 25 dollars for one of those usb "microscopes" just to do this repair.
I've been searching locally for a replacement for CC772 which according to schematics is 0201 12pF 25v. Though i closest i can find is 15pF 50v. Would that work or does it have to be 12pF specifically?
The resistor R2836 upon closer inspection seems to never been installed.
Sincerely,
Rick....Leave a comment:
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Measuring resistance to ground using the SMBUS_3V3_BATT_SCL and SMBUS_3V3_BATT_SDA test pads I get an unstable reading that will not settle. It acts a bit weird, the first moment I touch the probes to the testpad I get a reading of about 10 kilo ohm and rising fast, when I then touch the other pad I get a reading of 1.3 mega ohm and dropping slowly, when i then touch the first pad again I get the same mega ohm reading that slowly lowers. If I then wait a bit and measure again, the same thing happens again, first about 10 kilo ohm and rising fast until one switches pads at which point the resistance...Leave a comment:
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A1990 820-01814-A dead not charging - need help with diagnostics.
Good day everyone,
Let me preface this with letting you know that I have a smalltime computer repair shop but do not have a lot of experience when it comes to board diagnostics. I am good at soldering etc but finding the issue if there isn't an obvious burnt component is not my strong suit.
The other day I got a customer come in with a macbook A1990 (motherboard 820-01814-A) that would not turn on and had previously been getting the warning message that the battery needed servicing. (Most folks seem to ignore that message, just like the check engine light in vehicles.)... -
DELL LATITUDE 5285 (MB="LA-D89") schematic and boardview requested.
Good day everyone.
Got a dell latitude 5285 with motherboard version LA-D89 in the shop today which won't power on. So I opened her up, disconnected the battery and hooked up a charger to see if anything stands out on the board.
I was instantly greeted with the evil glow of a burnt component. Turns out that what looks like a mosfet with silkscreen marking U7 next to it has burnt out. Been looking for a schematic and boardview to check which component it is but have not been able to find one.
Anyone on here have the files laying around? -
Thank you to those who posted the boardview and schematics. I am still left with one question. Does anyone know the value of C313? I have a t430s that has image but no backlight, checked the board and found F7 and C313 to be damaged. The value of F7 is conveniently silkscreened onto the pcb (3A 24VDC) and is a 0402 size package. But still need to know the value of C313 in order to replace it. The schematic lists "SC1U25V3KX-1-GP" next to C313 but having a hard time deciphering that.Leave a comment:
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So very much appreciated. Thank you so much for sharing....Leave a comment:
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820-01958-A no power sys led = white when charger is connected.
Hi everyone.
First, let me preface by saying that I do not have much experience with diagnosing damages in motherboards other than visual inspection and checking simple short to ground faults.
But I do learn quickly, and really want to learn how to properly diagnose motherboard faults. If someone could have the patience to go over this board with me, it would be greatly appreciated.
A customer came into my shop with a A2179 MacBook with an 820-01958-A logic board. The reason for bringing the laptop in is that the laptop stopped turning on.
First thing... -
If anybody has this schematic, I would greatly appreciate it if you could share it with us. Need it to identify a component that blew up on a customer's board, and so far had 0 luck in finding a schematic. Might have more damage than just the obviously blown part, as the customer indicated they were getting warning messages that the fan(s) had an issue, which they thought to remedy by using a fan cooling pad, until it stopped working all together.
Just to clarify, motherboard part number: DA0X36MBAE0 Rev. E for an HP spectre x360 convertible model 13t-ap000.Leave a comment:
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Re: Imac A1419 27" 820-01134-A Need Schematic & Board View
thanks for sharing.
very much appreciated.
Leave a comment:
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Re: New Members - please post your introductions here
Hello everyone.
My name is Rick, I run a small-time computer repair shop in Ecuador working with any brand computers including apple products even though i ha7e them with a passion haha. Here to pick up the odd boardview/schematic and ask for help whenever I get stuck.Leave a comment:
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