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[HELP]a1990 820-01041 NOBOOT, STRANGE!
- Thread starter phantom
- Start date
It is 3.3V SPI chip, so TL866 should work.
Just need to get an adapter to connect its small package.
drive.google.com
Just need to get an adapter to connect its small package.
A1990 820-01041-A UB090 .bin
drive.google.com
You can use dual input MOSFET from another board model.
I hope you made UB090 backup.
Did you compare diode mode and voltage readings with U2890?
Did you check all resistors connected to non-working CD3215 chips?
I hope you made UB090 backup.
Did you compare diode mode and voltage readings with U2890?
Did you check all resistors connected to non-working CD3215 chips?
please 2informaticos...i'm going crazy....
i'm sure at 100% that all cd3215c00 are ok... all resistors around are ok!
only one port goes to 20v....
i don't know what else to do...
Diode readings of u2890 is the same of ub090
on u2890 (port xa, the only one working) i have
PIN 1/2/3 3,3v
PIN 5 0v
PIN 6 0v
PIN 7 3,3v
PIN 9 3,3v
on port xb and on ub090 (ta/tb)
i have
PIN 1/2/3 3,3v
PIN 5 1,1
PIN 6 0,9v
PIN 7 3,3v
PIN 9 3,3v
i'm sure at 100% that all cd3215c00 are ok... all resistors around are ok!
only one port goes to 20v....
i don't know what else to do...
Diode readings of u2890 is the same of ub090
on u2890 (port xa, the only one working) i have
PIN 1/2/3 3,3v
PIN 5 0v
PIN 6 0v
PIN 7 3,3v
PIN 9 3,3v
on port xb and on ub090 (ta/tb)
i have
PIN 1/2/3 3,3v
PIN 5 1,1
PIN 6 0,9v
PIN 7 3,3v
PIN 9 3,3v
Last edited:
You should tahe the readings when the charger is connected to corresponding port.
Can also use an o-scope to compare TBT SPI signals, according with the powered ports.
U2800 and UB000 are also connected to TBT SPI chips and can affect them.
May suspect UB000, as none of its ports switch to 20V.
You should also remove and check (out of board) each dual MOSFET paired with CD3215 chips; except the working one.
Can also use an o-scope to compare TBT SPI signals, according with the powered ports.
U2800 and UB000 are also connected to TBT SPI chips and can affect them.
May suspect UB000, as none of its ports switch to 20V.
You should also remove and check (out of board) each dual MOSFET paired with CD3215 chips; except the working one.
You can change them, but should be better to check them anyway.