Search results

It was PP3V8_AON. Specifically, the subrails for WiFi and for HDMI. It's unclear if WiFi was caused by my, but HDMI was definitely from the prior damage. I will note that U7700 had a sticky circle on top of it near one of the edges when I first got the board. Looking at the boardview, this edge...

There are AM wifi IC's, just need to be bound to the CPU. So you're saying it's more likely to be problems with generating those rails than some kind of short?

I found the short, and fixed it. I reassembled the board, but the short came back. Narrowed it down to UR500 (audio codec?), and removed it. The only three IC's not present at this point are that, UH904 (HDMI MUX?) because it shorted out and I assume it isn't needed to boot, and the WiFi IC as I...

Cables are good. What's next?

Update 2: I can't find the short. It's a 0 ohm short, and no amount of amperage (6.1A at 1.2V) produces heat on a thermal camera. I've pulled off just about every IC and MOSFET that's either directly connected to PP3V8_AON, or indirectly past a csense or an inductor. This includes the WiFi IC...

Update: P3V8_AON_WLBT is shorted. I am actively praying not that the WiFi IC isn't dead. Wish me luck!

Hello, this MacBook is acting strangely. USB-C and Magsafe are able to get 20V for about a second, before the board crashes and it renegotiates. This is done on an infinite loop. i found evidence of liquid damage, namely some corroded components and some trails on the board. Notably, the SPMU...

I'll do that once I have new donors for each port since both are currently nonfunctional as described above.

It's generating 3V3 UPC LDO and 1V5 UPC LDO. 3V3 S2 LDO is also generated. 1V8 UPC LDO is the only one that isn't generated. When magsafe is connected, 3V3 and 1V5 UPC LDO is generated at all 3 ports, but 1V8 UPC LDO is not. I don't know if they're only supposed to generate it when their port...

I have the XZZ schematic for 820-03286.

Alright, so I swapped the SN25A for both USB-C ports with the ones from the donor board, as well as the ROM. This board was known working, just iCloud locked. However, it has been through numerous heat cycles as I have pulled many components off it it, so the SN25A's and/or the ROM may be heat...

I did that to see if there was potentially a partial short that was causing the charger to drop voltage. Maybe I should read how PD works lol. Those pins are 1.49 on diode with my meter. This is compared to 1.481 on a known working port. Got it, didn't know the ROM was paired too. Apple bad...

Injecting 5V directly into the USBC Power Input line (PPVBUS_USBC2) saw a 0.8A draw for a couple seconds before it stopped drawing. That indicated to me that it was a communication failure causing the drop on the ammeter. CC1 and CC2 were both normal, which brought me to the SN25A. I thought...

Hello again, this MacBook is acting strange and I'm struggling to figure it out. Here's what I've done so far: At first it would charge fineish. Magsafe and DFU port charged just fine, drawing 70W and everything. The other USB-C port had no draw at all. Specifically, my meter went from 0.016V...

Sorry for taking so long to reply, it was fixed with an ethernet connection. Thanks!

I feared that was going to be the answer. There's nothing that stands out about the per-port behavior I listed?

Hello, I'm working on an 820-02382-A. It has no power. After verifying all power rails were good, I swapped the CD32's from another A2485 (M1 Pro version, not M1 Max). While installing them, i lost track of which one was for the DFU port, and which one was for the right side port next to HDMI...

Quick update: I haven't tried anything new with hardware yet, but it failed to boot into Internet Recovery. I tried again to see if I could potentially install MacOS (however slow it'd be) and run commands to check things, but after multiple hours of waiting it errored out with -2003F.

Hi, thanks for the welcome. I have fully charged the battery, but I don't have a new one to test with. I can try another touchpad+cable, I'll get back to you on that The fans never maxed out, no. They spin slowly while the MacBook is on which is about what I expect

Hello, I have an A1990 MacBook that was running very slowly. I'm not sure why I jumped to this, but I went straight to doing a DFU restore (and tried a revive later). After doing the restore, I got the flashing folder icon, this is expected behavior. When I try to enter Internet Recovery, the...