this should help
Lexmark printers with "Hardware Error 0502?
Published on February 11, 2006 in hardware
. 252 Comments Tags: 0502, error, fix, hardware, lexmark, printer.
Good tip for the Lexmark All-in-one inkjet printer
owners (mine is the X6170
After some months of use, your printer might get the habit of stopping in the middle of a page and showing "Hardware Error 0502" on the LCD display. If you leave the printer alone for a while, it might start printing again. Then again, it might not. Pretty annoying.
The Lexmark support site
will let you power off, remove the power cord for 30 seconds (!!), take out the cartridges and fiddle with some encoder strip. This whole procedure might take you up to 30 minutes and it will not help
(been there, done that).
The real answer is given by a person called 'clem':
Hardware Error: 0502.
On the multi function machine seems to be a coating on the metal rod that the cartridges travel on. Just wipe this rod with a kleenex and the problem seems to go away
. Somehow it presents a drag on the cartridges and causes an error.
This works! Clean the ****** with a paper towel (another page talks about re-lubricating the thing, but that was not necessary in my case). The towel will be black (ink residu, presumably), but there you go printing to your heart's desire again