water damage to the left speaker channel circuit caused an internal board short that has been carved out and damage to various capacitors. I removed both chips ur630 and ur600 both were burnt. Im not sure how to track down this partial short. Any suggestions would be greatly appreciated.
The fuse is blown on ppbus and im getting 12.24v to the ppvbatt side of the fuse
TheNuclearOption
Member
Last Activity: 08-07-2024, 12:01 AM
Joined: 01-30-2024
Location: British Columbia
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Macbook Pro (820-2773) 20 ohm partial short on the pp3v8 power rail after water damage
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I'm not sure where to go from here? -
I measured again today, 19ohms and 16ohms. Is there a chance there is something wrong with my multimeter? Could it be a partial short moving around slightly?Leave a comment:
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I measure again, and now im getting around 4 ohms. seems to keep dropping. Im gunna look at the internal short again
edit: I injected 1v into ppusb_aon and it's still only drawing 0.05aLeave a comment:
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about 17 ohms on L5840 and and 14.5 ohms on LF800. That seems very weird to me since I just measured them and got the resistance I mentioned last post....Leave a comment:
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I'm getting 23.7 ohms on the 3 inductors (L5840, L5820, L5800) on the pp3v3 rail and 21 ohms on the inductor (LF800) on the pp5v rail (same resistance as the downstream ppbus)Leave a comment:
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Okay thank you. Is that too little ohms for the downside stream of ppbus_aon?Leave a comment:
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Did I get that reading right? Does that mean there's most likely a partial short still?Leave a comment:
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Yes I removed the blown fuse. I'm not sure what side's the downstream side but ppvbatt (bottom pad on the motherboard in the photo) is one side of the fuse ppbuss(top pass on the photo) is the other. Ppbuss was showing a short to ground previously until I carved out the internal short. Now it's showing 21 ohms I think. I'm not sure if that photo comes acrossLeave a comment:
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My mistake, I'm getting 12.24v to ppvbatt and 21ohms I think to ppbus.
I removed my fuse, it's blownLeave a comment:
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There was an internal short. I was able to carve it out. Ppbus is no longer shorted to ground but it is measuring at 21 ohms. I'm getting 12.4 volts at ppbus when plugged in. Is a partial short. Likely still? It's drawing 0.01 amps now on ppbus...Leave a comment:
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Thanks for the replay.
They all measure at 0.5 ohms (a dead short I think)
What else can be done if they are shorting to the next layers? Cut them out?
These are all part of the left speaker channel....Leave a comment:
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HOW BAD IS MY PCB DAMAGE A2338 820-02337 water damage burnt caps
Short on ppbus. Taking 3a at 1v and nothing is heating up. I have at least 3 pads that are badly burnt from capacitors. Ive scraped (at least attempted to) not sure how good I did? Are these possibly containing internal shorts? Do you think they need to be scraped more?...
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I injected ppbus_aon with 1.2v and the short showed up on the pmic when I used a can of freeze. Before I source a board and replace it, are there other things that could cause this?Leave a comment:
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A2338 M2 short on main power chip
I have a short on the main power chip. Is swapping a chip of a donor board possible? Is there anything else I should check first?
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Im not sure if my multimeter is measuring correctly, its cheap. I have it set to dcv (2). Im measuring 0.14v to each side of the fuse on the ppbus_aon and ppbusvbat_aon. im measuring 0.015 to both socLeave a comment:
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MacBook Pro 13'' M2 A2338 get 5V 0.01-0.02a does not boot. 820-02773
I bought this laptop with water damage. There is corrosion on the logic board (ive included some pics). I removed the cr634 capacitor that was burnt on the ppbus line. The pad is still shorted to ground. I'm not sure how to proceed from here, any suggestions would be greatly appreciated.
The other areas ive included in the pics are the backlight circuit.... -
A2338 water damage with burnt charge port connector
Hi everyone, I bought a damaged a2338 MacBook pro with water damage and I'm hoping to learn how to fix it. I've worked on electronic for a long time for never attempted repairing water damaged components. The charge port connection on the motherboard along with the USBC connector is burnt. I'm hoping this is worth my effort and I'm not wasting my time. I've sourced some parts but first I was wondering if there was a way to check to see if it was Beyond repair if there was a fried CPU. Is there anything I should check before I order parts? -
Hi, I bought a broken A2338 and I'm excited to attempt a repair. Found this place immediately when looking for schematics and it seems like a great community with great resources.Leave a comment:
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