It's alive! Thank you so much for all your help.
Apple wanted $400+ to replace the logic board, ebay had it for $200+ but at the end it ended up being a $5 fix for capacitor + shipping. All thanks to this forum and the wonderful contributors. š
pcash0007
Member
Last Activity: 04-29-2024, 02:12 PM
Joined: 02-14-2024
Location: SLC, UT
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My apologies for the cross posting, I created a new post with a link to this but the two seem to have gotten merged somehow
I remove C6553 and the resistance between F7000 and ground increased significantly into mega Ohms. Now when the power is connected after negotiation, it jumps up to 20v , 1A. I'm waiting for the replacement capacitor, once that is in place, I'll put the board back and see if it boots up.
Thanks for all your help so far.Leave a comment:
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Starting a new thread, the concern on the original thread changed and did not want to mix them up, continuation of
[url]https://www.badcaps.net/forum/troubleshooting-hardware-devices-and-electronics-theory/troubleshooting-laptops-tablets-and-mobile-devices/3230642-dead-2018-macbook-pro-a1990-820-01041-07-stuck-at-5v-0a#post3256393[/url].
I applied 2v(1v did nothing) to F7000 and noticed 2.5amp draw. The hotspot was C6553. I did not see any increased heat at any of the DRMOS near the CPU, should I be applying voltage at a different place to test the DRMOS?
Thank...Leave a comment:
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Cool. Thank you.Leave a comment:
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I'm trying to find a replacement board for this laptop. The number of the board is 08-01041-07, I see a lot of 08-01041-A on ebay, are these interchangeable? The year(2018) and model(A1990) match on both the boards. Please Help. Thank you.Leave a comment:
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Thank you [USER="302067"]reformatt[/USER].
I think the board is toast. I did not get to check with thermal camera yet, I plan to do it just to experiment and learn.
I see that resistance between TP_PPBUS_HS_CPU and TP_PPVCC_S0_CPU is ~9ohms which leads to me to think one of the DRMOS U7210 - U7230 is shorted.
To determine which DRMOS is shorted, should I introduce voltage @ one of the PPBUS_G3H fuses?reformattLeave a comment:
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Another question....PP1V8_SLPS2R seems to be the enable for U7000 which makes PPBUS_G3H. PP1V8_SLPS2R has 0V. Is it possible that's why PPBUS_G3H is zero?
The resistance between ground and the coils near CPU is also very low even lower than PPBUS_G3H and the coils.Leave a comment:
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Oouch, that does hurt, but it is what it is. Thank you for helping me put this to rest. I'll look around for a replacement logic board.Leave a comment:
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Thank you [USER="295753"]mon2[/USER].
Looks like the coils around the CPU are L72xx, L73xx, is that right? If so, the resistance between PPBUS_G3H and these coils is between 6 - 14 ohms
LA340, LA640, LA650 - 6.3 onms
L7211, L7221 and L7231 - 8.2 ohms
L7410, L7420 - 13.9 ohms
Also the measurements in my previous post and this one are with the board removed with no other peripherals attached.
Thank you.mon2Leave a comment:
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Thanks [USER="302067"]reformatt[/USER].
Visually everything looks good including the C9081.
Few questions...I'm having tough time finding where the CPU coils are, help please, a part# or TP# or something I can lookup in FlexBV.reformattThanks [USER="302067"]reformatt[/USER].
Visually everything looks good including theLeave a comment:
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Dead 2018 Macbook Pro A1990 820-01041-07 stuck at 5V 0A
First time looking at a logic board this closely, learnt enough from videos and forums here to be dangerous
I was doing a OS update when the screen went blank at some point. Does not seem to be in DFU mode (checked using apple configurator).
PPDCIN_G3H is 5.16Vā
PPBUS_G3H is 0.045V
Resistance between TP_PPBUS_G3H and ground is 23.8 Ohms (which seems low)
F7000 and F7001 seems fine.
From what I learnt seems like there might be short on the down side on PPBUS_G3H.
Is injecting low voltage and see what... -
Hi Everyone, from Utah, USA. Have couple of broken speakers and a laptop. Trying to experiment and learn a bit of electronics and board repair....Leave a comment:
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