Many of you have read my previous posts ranting about the many problems I was having with my HP Prime, and how I finally contacted HP Customer Service for a replacement. Well, today I received the promised replacement and things are looking up. First, it should be said that HP service in this matter has been stellar, and whatever else I might say about the product, I have no complaint whatsoever in the way HP has handled it. I was sent a new unserialized calculator w/o accessories, which needed to be charged before use, but was otherwise in perfect working condition. So far it has not had any issues and runs all my programs and Apps properly w/o crashing or errors. Yes, it will do an occasional reboot/reset when making an illegal operation or encountering one of the many firmware bugs, but the only outcome is loss of work done since the last normal power Off. No frozen keyboard or display, no rebooting Apps or Esc key, no random Settings changes, no slowdowns and most importantly no reformatting the flash drive to recover the OS and proper calculator operation. Also, the auto power down function seems to be working now, whereas before it would seem to randomly cycle between shutting down every couple of minutes and not shutting down at all.
The first thing I did after charging the battery was to do C F O On and performed the 5. Evaluation 4. CHK BAD FLASH test, with the result that there were 4 bad blocks on the flash drive, whereas there were 7 bad blocks on the first Prime. So, I'm really thinking that this has nothing to do with the problems I was having, and is just the result of the factory low level format. These bad block have been cordoned off, and no data or programs are ever saved on them. More likely RAM is getting corrupted and then written that way to the flash drive. To prevent or at least minimize any future corruption of the OS that would require another reformat of the flash drive, I am taking the followings steps:
1) Do not use the Connectivity Kit (CK) backup/restore feature. It simply does not work and corrupts the OS. Instead, I copy/paste/save all my programs as ANSI text files from the CK to Windows Notepad. If I need to restore them, I reverse the process.
2) Switch off RPN entry mode except when working in the Home screen, since it really isn't very useful outside of Home and will actually crash the calculator and even lead to a flash drive reformat if used in a Spreadsheet.
3) Avoid using any CAS commands or functions in a PPL program, if a non-CAS alternative is available. For example the CAS sqrt() function gets all messed up when using LOCAL variables, so I simply use ()^.5 in its place. Also, if you do use any CAS commands or symbolic forms in a PPL program, first debug the expression in the main CAS screen, and use the form CAS("<expression>") in the program. This will create a mini CAS environment when executed in the program, much like the Command Prompt in Windows creates a DOS box.
4) Develop and debug any new program in the Emulator, and then transmit it directly to the physical Prime, using the Send soft key on the Emulator. Note that the CK must not be running when you do this. Unfortunately, this procedure does not work reliably with Apps, such as saved Spreadsheets, so I typed all mine in manually on the new Prime.
5) Do not do a firmware update. The factory version is the most current, and you just risk bricking the calculator if you do. It could be many months before HP issues a firmware update, which would hopefully address the most serious firmware bugs.
6) If you are having serious reliability problems like I was, consider contacting HP Customer Service and requesting a replacement. You may have a lemon.
The Prime is definitely a work in progress, and I hope they can catch up with the potential of this platform.