Hi Stephen,
I already tried with 2 other batteries. this one has 168 cycles. I could boot with the battery pluged in but with trackpad cable disconected. It booted slow, and the fans where running noisy, and that's how I found information about the battery.
I've performed a new DFU Restore, this time with last version of macos Sonoma on both macs, and with the last iBridge. The same result. Please tell me this, DFU Restore operation is reflashing the entire T2 ROM file?
I have some KP messages.
I forgot to mention the fan where running fast but nothing was heating on the board, I've checked the CPU, GPU, Nands, memory, T2 chip, they where at max 40 degrees(Celsius)
When I read the KP message - about a namespace error, I thought there's something about ACPI namespace and the ACPI tables are part of T2 ROM bin file. That's why I've asked you to help me with a clean T2ROM bin file.
The old battery had over 750 cycles, and I experienced something with an A1989 model, wich was working normal until the battery percentage was drawing down to 60% - 70%, when suddenly the system was crashing, rebooting by itself with KP message. So my explanation is that could be the same with this A1990, perhaps it was performed a major update, without the addapter pluged in and during the process, the system crashed and the bios was corrupted.
I have another macbook in the same stage, an A2251 one. At this one I have no info about the battery, but I let it to charge at full, and after few hours I measured the voltage - first 8V, after 7V -decreasing, with the battery flex cable un plugged. I think this one also had a broblem with the T2ROM bin file corrupted, probably the same cause. I could be wrong but I have no other explanation. So could you help me?