I recently snagged a beautiful 9830a from a long-time HP reseller in San Jose. The machine is in spectacular cosmetic condition; it looks as if it came out of the box just a few months ago.
It has the 8K memory upgrade and I grabbed a slew of ROMs as well as an equally-snazzy 9866 printer.
Everything works great except the tape drive. I can read the pre-recorded Math and Stat packs reliably; the system test cassette reads perhaps 20% of the time, and although I can successfully MARK the two NOS HP tapes I got with the calculator, I've never been able to write anything to them and read it back without getting an ERROR 59 (checksum error) or ERROR 58 (misc tape error: door open, STOP pressed, clear leader problem, etc.) In the latter case there is no obvious physical problem I can see, and yes, the internal tape light works.
I've cleaned the head with alcohol and wiped it down with a microfiber cloth.
Now, this could just be cruddy 35 year old tapes. I've ordered new tapes and a head deGausser which I should receive next week.
The tape drive makes a continuous "tap..tap..tap" sound as the tape is read or recorded at normal speed. With the top of the computer off, a finger on the driving spool motor will feel each "tap" distinctly. Is this sound normal? And does anyone have any suggestions for things I could try?