Hi., I am working on a Apple Macbook Pro Retina A1398 15.6" 820-00138-A., Not turning on (Dead). There was liquid spill near U7200 & slight green stuff near the SMC. Replaced the U7200., Now I get the green light, but there is a severe short on PPBUS_G3H, almost 0 ohms. Just to narrow down the trouble shooting & verify where the short was, I removed the 2 fuses F7140 & F7141. After removing the fuse I surely get back PPBUS_G3H 12.8V on L7130, now atleast I know that the short is across the fuse. Has anyone found the short on this logic board after the fuses or can anyone inform me what further components should I check. The boardview which I have is not of the exact match or anyone has a board view for this model. Thanks
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Last edited by mferna14; 06-27-2020, 04:59 PM. -
Re: 820-00138-A Q7706 PPBUS_G3H Short
U can search on google for the but doardview with the board number to download boardview -
Re: 820-00138-A Q7706 PPBUS_G3H Short
Please view the photos, all the mark caps have reading of nearly 0 Ohms across them.. Do you think the CPU is shorting the caps. Any ideas will be appreciated... ThanksAttached FilesComment
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Re: 820-00138-A Q7706 PPBUS_G3H Short
What's the exact resistance to ground? ("almost 0 ohms" is not precise enough)OpenBoardView — https://github.com/OpenBoardView/OpenBoardViewComment
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Re: 820-00138-A Q7706 PPBUS_G3H Short
Seriously the meter reading across all the caps you see in marked on the photos shows 0 ohms., something is completely short to ground, either its the CPU/GPU or one of the caps, which I am doubtful now since the caps on the CPU SR1ZX too when I take a meter reading it almost 0 ohms. Physically I do not see anything burnt or bursted. Do you think its the CPU/GPU since the tiny caps on it too are show 0 ohms???Comment
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Re: 820-00138-A Q7706 PPBUS_G3H Short
Just received one of these today with dead short across PPBUS_G3H. No prizes for guessing where the source of that one was.
U7310 was short, and so was the CPU; confirmed with voltage injection and thermal camera. So whenever I see this, I check the driver and sure enough, there was the smallest amount of liquid damage to the sense pins of U7200. I really hate how these things self destruct with something like this.Attached FilesLast edited by reformatt; 05-20-2022, 01:50 AM.Comment
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Hi Folks
I'm looking for a extreme high current short killer solution for a reasonable cost.
I have an LGA1700 motherboard (ASUS PRIME Z790-P WiFi) where I exchanged the LGA socket already 3 times, and every time after the socket exchange I get a short of power supply lines VCORE (V variable) and VCCIN_AUX (1.8V).
After taking off the socket, the shorts dissappear again.
The soldermask on the socket is already partially demaged from the heat, so I have reconstructed the soldermask by manually painting the missing soldermask parts with a very small top of a...10-15-2024, 10:13 AM -
I check PPBUS_AON and there is a short present on the line, the computer shows a short when testing for short to ground, so when I inject voltage into the line, I get 0AMPS so no short is showing up. I have replaced a blown cap on this board that exploded and tested for the short and it is now removed. Any suggestions? I tested voltage at the line when the fuses are connected and I am getting 1.2 Volts at the line.
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Hello everyone,
I'm trying to repair my old Acer Nitro 5 (AN517-54-55T5). I've already bought a new laptop, so this is more of a learning project. For the experience, with no high expectations of success.
Well, my decice specs are the following:
Model: Acer Nitro 5 AN517-54-55T5
CPU: Intel Core i5-11400H
GPU: NVIDIA GeForce GTX 1650
Motherboard: GH51G LA-L181P Rev:1c
The symptom:
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Hi all,
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Bought replacements from Aliexpress and replaced them afterwards. Tried the card but still the saw the fan spin for a split second... -
Hi All, I have a 9th Gen Dell Optiplex micro PC motherboard which doesn't power on. When I connect the motherboard with power adapter, it goes into safe mode and turns off. So from info I have gathered online, it looks like there is a short circuit on the motherboard. So can you guys help me with figuring out the issue?
I am new to electronics repair, so my queries could be naive but I am ready to learn.
So I have a multimeter and a solder with me. But I can try to get a variable voltage power supply with a thermal camera as well. From what I seen online, best way is...
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