I replaced the drum unit on my toshiba e studio 170F, but the "drum unit warning" error still shows and the alarm light is blinking. How do I clear it?

This is an advance reminder for you to order a new drum, you do not have to replace it until it asks to do so. A drum unit is rated for 20,000 pages (5% coverage), it depends on your usage, if there lots of graphics of dark color, you have to replace it before it expires. You can reset it, if there is no quality issues. Procedures:
[x]-key to press, {{ Display on the LCD}}
[Menu], [5], {{5 Default setting}};
[2], {{2 Scanner & Printer}};
[0], [4], {{04 Reset drum counter, 1=Yes, 2=No}};
[1] {{Reset Drum Counter, are you sure?}};
[Enter].

FYI: I would recommend that you put a label "Drum reset" on the drum unit, remind yourself, that you must replace it, once you have a quality issue.

Hi,
maybe the roner cartridge you inserted is not supported by Toshiba e-Studio 170f. This may be one of the reasons that the machine can't recognize the toner cartridge.
Reinstall the toner cartridge that you have. If that doesn't fix the issue try to replace the toner cartridge with new one.
If you continue experiencing this issue contact your technical support team.

the drum & its cover is one unit
just remove the toner cartridge & put it in the new drum unit cover

how can to reset error code c21 my toshiba e-studio 166 printer

perform this progarm after replacement of drum.

PRESS MANU 52041 START/ENTER

Yes, this is a link to it. For Toshiba eStudio 170f Operator's Manual.
http://209.167.114.38/dealers/opg/support/manuals/Operator_Manual2005614111924.pdf

http://www.service-docs.com/store/search.php?searchstring=TOSHIBA e-Studio eStudio 170F&showresult=true&exp=&resultpage=&categories=&msg=&search=search.php
Looks like this costs $12.99 and includes user manual, service manual, parts manual, etc.....

here is the link for toshiba
http://www.visualhawk.vcc.ro/toshiba_error_codes_en.html


If you need further help, reach me via phone at https://www.6ya.com/expert/david_eb7ea98642566cc6

It's time to replace the drum. If you don't, it will stop working soon.

Fax display screen always reads, "Auto receive". When attempting to fax, the busy light flashes. Busy light stops flashing for 30 seconds, then starts flashing again.
Above is the default settings for the fax.

NGB0 indicates signal error or line condition error.
U need to check the phone line. U can hook any single line phone to the phone line, check for tones without background noise.