BQ20Z75 won't unlock

use paint to  save whatever you want to paste as a jpeg file ,  and then use the insert image button to insert the jpeg file

did you enter the unseal and full access  keys using the 2 word write command as shown in figs 26 and 28  in

0882.slua421a quick start guide for bq20zxx family gas guages.pdf

FYI the pack will now reseal after every reset or power cycle once you sent the lock command once.

not sure this is useful... is there a way to zoom?

I'm not using BQeasy evm software.  My host processor is doing it.  There is no reset or power loss during this time.

not sure you can really help me if you can't see the waveform.  I've read the documentation thoroughly and I've done the correct things.  I am not new to this chip.

I can see your waveform ok , just clicking on it opens it up to examine closer, but I am not so familar with the IIC waveforms that I can just look at it cold and point at the problem. If I were you I would double check to ensure that both words for each key are being written without any interuption in between, hence the need for 2 word write command on EVSW as opposed to trying to send two words with seperate commands. I guess you sghould be trying to emulate what the EVSW does. Have you tried hooking up the EVSW and trying to capture the relevant bus activity for comparison ?  

I am writing the two words in the command as separate I2C transactions. There is nothing in between but I will try it as one transaction and see if that changes things.

The unseal and full access commands consist of (2) two word writes each in their own I2C transaction.  This is how iI am doing it  and how BQEVM software does it as well. So still need an explanation why it doesn't work.