Message on printer screen saying needs service. What's wrong?

If you already followed these instructions, the last thing to do is to service the printer. I don't know of any self-fix options for this printer. It's worth validating that you've already completed these steps as described.

Carriage Jam or Carriage Blocked Message Displays on the All in One

No it's not worth having it repaired.

you need to reset the message by going into maintenance mode hit these keys very fast
menu * 2864 and the screen will flash and say maintentance here is a link to the service manual
I downloaded it free http://www.scribd.com/doc/18198278/BROTHER-MFC8460n-Series-Service-Manual
Chapter 8 has the codes to enter after going into maintenance mode

On the screen where it says "Call for service," there should be an error code (starting with "SC" and ending with a 3-digit number). This code can tell you what is wrong with your machine -- what code is displayed?

Does turning the machine off (with the main, orange power switch) and then back on clear the error message?

It's worth repairing, That error on a Canon is saying that the printhead is bad, not your cartridges. The part number for your printhead is stamped on the side of the printhead could be QY6-0049-000 but I'm not sure.

There is probably nothing wrong with the printer, but it may not be be receiving all the dope it needs. Usually the printer needs a CR/LF signal at the end of the file to print. If it doesn't get that it will assume that it hasn't got all the file and will hang. This may be a setting in the application producing the file, or a setting on the printer itself (i.e needing either a full CR/LF signal or just one of these). Don't like the idea that it doesn't print its own test page though....

I bought my Brother Printer all in One for $50.00.

Go for it!

This message means that the printer thinks the waste ink pads are full and so
> it refuses to print until the pads are replaced and the waste ink (protection)
> counter is reset.
> In practice the pads will not be full if this is the first time you have
> received the message so all that needs to be done is to reset the counter. Next
> time you must replace or clean the pads.
> Go to http://www.ssclg.com/epsone.shtml and download the utility.
> Install it, run it and exit it from the main window, now go to the icon in the
> system tray and right click on it. Select waste ink or protection counter and
> select reset. If this gives trouble then uninstall the Epson status monitor and
> try again (you can install the status monitir again afterwards).
> The irony is that the more you use an Epson printer the more reliable it will
> be (due to the heads being kept in good condition) but the people that use
> their printer most will get this message earlier than others. Some people never
> see this message. It is a good printer and well worth the effort of doing this
> at no cost.
> Tony
> MS MVP Printing/Imaging
>
The SSC service utility won't reset the R1800 counter.
The Epson service program is needed and can be downloaded from:
http://www.2manuals.com/

The R1800/2400 service manual can be downloaded from that site.
If you want to have a go at replacing the pads, then instructions are in
the manual.

Wrong you can save the printer by installing an external waste ink tank and resetting the code.
don't replace the ink pads install a external waste ink tank instead, then reset the printer using reset program . . search on eBay for epson waste ink tank comes with reset program. I got a tube one for mine and it saved my printer.

The message indicates that the laser scanning head is defective. Lexmark calls it a printhead. Unless you want to spend a lot of money, it may not be worth fixing. A new part runs over a hundred dollars.