BQ20z75 BQEasy issues

The device may have ended up in ROM mode. You can try sending an SMB Command 08 from the Pro screen. This will put it back into normal mode, if it is in ROM mode.

Thanks Thomas,

I tried to send command 08, a dialogue window pops out stating: "SMB Write Error, Error code: No Acknowledge: VB_T2H_NACK" 

Any other ideas? I was very surprised when I switched from BQEasy to SBS to check on the chip and see it was completely gone. I had gone all the way to step4 in BQEasy, without noticing anything abnormal. 

Exactly the same thing happened as I worked on second pack. Everything is fine up to step 4 in BQEasy, and I went back to check the status of the pack in SBS. Click on Refresh, the chip is gone. Is it not supposed to use SBS after initialized BQEasy? Thanks.

Step 4 is Chemistry selection. Did you lose communications at the beginning or end of the step. I saw that you made it through this step back in December. Is your setup the same as it was back then? You can try reloading the senc file to see if you can recover the device. Do you have the senc file? If not, are you using firmware v160 or v180 of the bq20z75?

I didn't check on the pack, just went through in one shot all the way to step 4. I checked pack status to get ready for the cycle, I usually keep scanning during charging and discharging. What's different this time is that I used the .dfi file came with the EV s/w, there are many versions, BQEasy suggested v-181, it turns out v-181 was empty. So I used v-180 in both cases this time. Since that happened in step1 of BQEasy, I didn't check the pack after finishing step1 until before I was ready to cycle the pack.So I can't tell what happened right after programming the flashing image. In the following steps as other files are written/read from the pack, all appeared normal. But when I went back to SBS the chip stopped to respond. Any suggestions? Thanks.

ps. Since I got stuck in step5 last time, so I started all over. 

Here is the v181 senc file. You can try reloading it into the device to see if you can recover the EVM. When using bqEASY, I would select the "Keep Existing Dataflash Image" button, if the v181 is empty. Using the v180 could casue a problem.

To load the senc file: 

Go to the Pro screen.

Use the Write SMB Word field. SMB Comand 00, Word 0F00. Press the Write button. This puts the device into ROM mode.

Use the Srec programming field and find the senc file that I attached. Press the Program button.If the program loads into the device, then that will be good.

(If the program did not load, then the device is not recoverable and will have to be replaced.)

Use the Send SMB Command field. SMB Command 08. This returns the device to normal mode.

Should I change the file to .dfi before I try to load it? Thanks.

No, leave the senc extension. The dfi file is a subset of the senc file.

I tried. BQ20z75 doesn't respond to 0x00 write operation, error message: SMB Write Word Error; Error code: SMB terminated: VB_T2H_UNKNOWN

I tried to proceed with Srec programming with the file you send, error message: Communication error! Error Code (decimal) =6

I tried to use BQEsay, Setup Step, to program Data flash image, it went through, but the chip still no sign of responding to any communication.

So it was the Program Dataflash image in setup that loaded wrong file? Thanks.

The device is probably not recoverable, if you cannot reload the device. There must have been a dfi mismatch problem with the device. I would choose the dfi that is already in the device for the new try.

I see, since without performing Programming Dataflash Image the BQEasy Setup step doesn't show a check mark, since I got stuck last time I get a little conscious about all the little details to get everything the way BQEasy likes. You can be too careful.