Good morning,
recently I had to unseal some battery packs for changing some configuration parameters and I followed the standard procedure I found in a post (I haven't changed any default access keys):
+ Disable Scanning in bqEVSW
+ Type 0414 into the data entry area of the Control field. Press Enter on the computer.
+ Type 3672 into the Control field. <Enter>
+ Select the Refresh button to see if the SS flag turns green.
+ If is does, then follow the same process to enter the Full Access pass codes. ffff ffff
+ If it does not clear, then the device may be bad or there could be a problem between the computer and GUI.
By applying such a procedure, it seems the bq34z100 has been unsealed (i.e. flags FAS and SS turn off and flash data become readable), but it is not completely true. In fact the device automatically switch back again to a sealed mode if:
- I send a reset command (0041)
- I disconnect (and connect again);the circuit from battery pack
- I flash it with a new .rom file
So it seems the bq34z100 remember forever once it has been sealed and it can't switch back in a full unseal mode anymore.
Moreover this situation is still more complicate when I try to flash it with a new .rom file (by using, for example, the "bq Single Station Tester" tool). If the bq34z100 has been previously sealed and unsealed, it is no more possible to overwrite all parameters of its flash memory and the tester tool reports an error. If the update of "Dynamic Pack Data" (i.e. serial no., lot no. and production date) are not flagged into the tester tool, the writing procedure can be passed. If I would like to overwrite also such data (i.e. if I want to write both a new the flash image and a new serial number), an error occurs.
Everything goes well if the bq34z100 is completely virgin, i.e. if no previous sealing and unsealing procedure have been done on it.
Please let me understand if this behavior is correct (and why) or if I'm doing something wrong. I think a procedure for completely restoring the unsealed mode should exist.
Thank you
Matteo