The Pioneer 210 is not exactly friendly towards DIY repair attempts, you will most likely need the service remote and service dvd. What type of burner did you install as a replacement: a genuine 210-dedicated model or the generic DVR-106 made for PC use? If it was the generic, that won't work at all: it doesn't have the CPRM chip that couples to the motherboard. If it's a true 210 spare burner, you'll need the service tools, although in some cases a Pioneer recorder will allow burner replacement without the service tools. Many of us have used the trick of opening both the original dead recorder burner and the replacement burner, and swapping their green controller boards. This gives the "new" burner the same CPRM chip and number as the "old" original recorder burner. The recorder will be fooled into thinking nothing has changed, so it stops asking for the CPRM service procedure. (You can swap the boards between any DVR-106-based burners).
The burner board swap trick doesn't always succeed in the older 2003 models like your 210. If it fails, you'll need the service tools to re-marry the burner CPRM to the recorder CPRM, even when the
original burner is disconnected/reconnected. Pioneer Video is out of business but you can get the service remote from Sony parts distributors as model # J-6090-203-A for about $40, or a "clone" of the service remote is available from
http://remotes.com/store/pioneer/ggf1381.html (I use this one). There are a great many posts on various forums regarding "home brew" service remotes: most of these don't work, risk damage to the recorder, or risk damage to the expensive programmable remotes involved (such as the Harmony). I advise sticking with a dedicated service remote.
The service data/ID disc is available from the same site that publishes instructions for clearing the CPRM problem:
www.pioneerfaq.info. From the home page, in the left hand bluegray navigation area, click on "DVR", then "Replacing HDD", then "DVRx20", then "Part 2". This will bring up the instructions for using the service remote and disc to fix the CPRM issue (the instructions say "HDD" but its the same for the burner, just ignore the final step of "initialize the HDD"). At the bottom of this instruction page you'll find a link to "leave a message": use it to request help in getting a download of the GGV-1256 or 1302 service disc.
If you haven't yet put a lot of money into repairing your old Pioneer 210, consider replacing it altogether with a like-new-refurb $159 Magnavox H2160 DVD/HDD recorder from
http://www.jr.com/magnavox/pe/MAG_H2160MW9_hy_RB/. It is way more advanced than the 210 and
much more compatible with todays blank DVD media (even a repaired 210 is still stuck with the long-obsolete 106 burner mechanism). Nearly everyone on AVS has moved to the Magnavox by now, its price/performance can't be beat and it has the modern tuner necessary for USA/Canadian digital broadcasts. The only advantage of the 210 (aside from being a gorgeous piece of machinery) is its bidirectional DV camera port. The Magnavox cannot
play out thru its DV camera port, it just
records in from it, like every other recorder. (The Pioneer 210, 310, 510, and 5100 were the only consumer dvd recorders ever sold with bidirectional DV camera ports.)