For $29/mo, we provide access to advanced level technicians who will answer your questions on any Macbook board related matter to the best of their knowledge promptly & walk you through how to solve your problem so you can deliver a working board to your customer.
Im not overly familiar with how this entire USB system works
Liquid damaged board corrosion and burn pad on UB300 and corrosion under UB400. Reballed UB400 and swapped UB300 for good chip.
Get 5v at fuse but wont go to 20v.
Ive poked around and found a few 3.3v lines but not sure of what all...
I put that on. It had an EFI passcode. I removed it no biggy. Its still running really slow. Starting to think its an issue with the SSD possibly? Although the mouse seems sluggish also so it seems like a Kernel Panic kinda of slowness.
Got a 820-3208 that had the bios swapped by someone and its running dog slow. I dont know how to clean the ME region or add the serial so needing some help.
Serial Number is C02KL348DRV7
Sticker on board is C02317201KBF9DHAK
I'm at home right now but before I left I checked 3v3out 1v1 ldo 1v8 ldo and some other power rails around those chips
1v1 was 1.08-1.1v
1v8 was 1.79v
3v3 out was 3.29v
??????there was one other 3v3 line that was also 3.29v
the ldo voltages I believe were only present on 1 chip at a time...
Liquid was around and down both USB C charging Circuits and controllers
Cleaned area and found 5 burnt traces
R3351 Burnt PPBUS_G3H pad - Ran jumper to R3451 PPBUS_G3H side and replaced R3351 with new 10K resistor
R3360 Burn via - Cleaned and checked...
Ok thanks for the info Duke. Ill be buying some now. I think I had some of these that I replaced on 2 other water damaged boards but currently out of stock. Ill see if the customer wants to wait or just roll with the software.
Thank you both
realmacmods didnt know you were on here. Yes seems to be working great. If you dont mind spilling a few beans what seems to be the root cause? Is there proof in older firmware that they dont drop voltage that low?
Is this literally a flaw in Intel Power States where the CPU is put at such a low...
Had a 820-3662 come in for random shut down. No liquid. Checked all the rtc stuff and caps normally checked. Seems fine.
Found a script online claiming the shut downs are caused by a lower power state bug in the CPU that causes failure when the CPU enters a lower power state.