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.
"Transplant the ME Region from your backup to the new BIOS".
When I did this, the initial defect came back, so I was able to deduce that the problem was with the original ME region. After some searching I was able to find a ME region version that worked perfectly with the BIOS and now the mac...
The last LED does not turn on. It just spins the fan, with no activity on USB and no image on internal or external monitor. I tested again with the original BIOS just to make sure it would happen again, and yes, it does.
According to the customer, the mac was used only a few times, and was left...
This has no password, but it is not possible to boot into MacOS. I have tested a few versions, but in all of them the mac takes a long time to load the bar and then shuts down. I tested with disconnected peripherals as well. Recovery mode doesn't work either. Apple diagnostic does not show any...
It worked! Initially the machine turned on but without any processing activity. Now it is working but the supplied BIOS file is password protected. Can you unlock it? Here is the original file in case you need it:
U2890 and surrounding resistors are in good condition, also with good resistance values according to the schematic.
Voltage values of the U2890's lines:
No, the machine will not power up when plugging the charger into any of the ports. I could only turn it on because the battery still has charge. L3500 and LB700 both have 0V (even connected to the charger)
When I plug in the charger, without connecting the battery, I get:
Hi, this mac had liquid damage and came with oxidation on the USB-C controllers on one side (U3200 and U3100). I did a cleaning but it was not successful. When I made measurements in reverse diode mode on the LDO signals, on all four controllers, I got:
I used another Topcase, installed the system over the internet, but it shows a critical software update. I don't know what else to do, what's left is to inform the client that the Touch Bar will not work.
This mac suffered oxidation in the u3900 region, I deoxidized it, replaced the damaged components, it worked perfectly. The customer decided to install macOS Monterrey and had Update Critical. I was able to update the macOS only when I unplugged the Touch Bar. Now the Touch Bar doesn't work at...