critical software update error board issue
hi friends,
I have 820-00923 stuck on software update error logic board issue. i.e. 1.88V not present on R4400 and R4490. any one have an idea is this a T1 issue or some thing else?
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Why are you looking here? The reset line is normally low (zero)
Reference: AND Gate - Logic Tutorial
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Baord is not enabling DFR either another ok board reset line communicate with 1.9V. other Ok board have 1.9V on R4400 and R4490.
@shaf2u - If you inject the voltage on the line the state should switch, did it?
yea injected but no luck.
Then we are looking at the wrong area.
@shaf2u Injecting voltage into T1 will not get bridgeOS to initialise which needs to happen to get voltage on your DFR reset lines. BridgeOS resides on the internal SSD which is why I wanted you to check that connector. You need to rule out the other problems that can cause your issue before determining it is a T1 problem.
You haven’t mentioned what you have tried like.
• Booting into safe mode.
• Booting from an external USB drive.
• Disconnecting touch bar.
• Disconnecting touch ID.
• Trying the board in a known good housing.
Critical update error on this board is usually a driver problem. If it is a board issue the problem will be on the J9600 connector or one of its circuits.
由 Chris Stables 完成的
Bro J9600 ? i think you would like to say it J4401. because j9600 only control Nand drive.
由 shafiq 完成的
@shaf2u No I am referring to J9600; the SSD is where the touch bar driver is. The touch bar driver is one of the common causes for the critical update error on this model.
由 Chris Stables 完成的