Error Code 21:10 after changing belt.

[CPS88]

I changed the belt on my old HP Designjet 500 after getting an error code 86:10.  I realized the belt was absolutely shredded.  I am all reassembled and looking good but now I am getting a 21:10 error code indicating a service station or print head problem.  The display indicates to call HP for service but that's a little out of the budget right now.  I see a good deal of YELLOW ink had leaked at one time or another but it's been quite a long time since I've actually printed with this plotter. I can see some sticky black residue too. Can anyone offer advice?  I watched a very detailed YouTube video to reassemble and was very careful watching and reassembling step by step. I even kept the service station screws separate (shorter) as directed in the instructions.  Is there some common problem I missed with the belt change? Can I simply clean up the yellow ink?  Do I really have to get a new print head?  And...just yellow?  I really need to get this plotter working!  Thank You! CPS

[Repairatrooper]

Three possible causes on this error code

1. The steps counted by the Service Station motor are not consistent with the expected length of the current movement.

2. The Aerosol Fan has reached its maximum current limit.

3. The Service Station motor has shutdown because of blockage.

If there was a lot of ink spilled into the service station I have seen cases where it will solidify and block movement of the sled that wipes the printheads. If the current head is the one that leaked you will need to determine if it was the head or if there is an issue with the ink tubes. I have seem videos online of people cleaning the service station but be warned it is a messy proposition.

Of note, newer revisions of the service station did not have the aerosol fan. If a newer service station is installed on an older plotter you need to update the firmware to avoid a error code for the fan not working.