Hello all and Happy New Year 2023,
Since end of 2019 I've venturing myself to use TDSxxxC/D in my own lab then buy some more and/or repair some other TDSxxx/C/D units.
The tekfwtool suite was really good (firmware, NVRAMs) and very fast. My return of experience involves now total of 8 units, everything went fine to upgrade, to un-brick but early this year I've found a serious problem with tekfwtool, maybe some of you suffered the same issue.
If for some reason your CPU board uses flash file memories TE28F160S5 model, after erasing then programming the firmware (i.e. upgrade from 6.3.e. to 6.6.e) then the oscilloscope will brick: happened to me on my TDS754D and my TDS784D erlier this year. However the tekfwtool software will do its job very well if the flash files memories E28F016SA, I have two spare CPU board with these flash and no problem.
After a few days of despair, the only solution was to modify the very slow tektool software to save one of my CPU boards but ideally if tekfwtool could cover both flash files memoriy models, this would be the best (tektool is ultra slow whatever you do, tekfwtool due to its 68K cookie installed in the TDSxxx/C/D is very fast).
The version of tekfwtool I've been using for more than 2 years come from this github repo
https://github.com/ragges/tektools where unless I'm wrong, the original come from
https://github.com/fenugrec/tekfwtool and here
https://github.com/svenschnelle/tekfwtool plus getcaldata as well as the floppy method (NVRAM and EEPROM).
As a safety, I recommend those of you using tekfwtool to first check what flash file memory model is installed on your CPU board or be prepared for serios brick, not fatal but you'll loose huge time.
I did fork while ago the repo from ragges to eventually make some modification here
https://github.com/tantratron/tektools where I've been always using National Instruments GPIB-USB and Macintosh computer.
Thanks again ,Albert