I have a roland sc545ex printer and there must be an air leak the ink doesn't fill the dammper, I can see air in the line if one of the feeder hoses so the head isn't getting any ink How can I find the problem and fix it

Check the damper and see if there is ink it in. There might be an air leak. If there isn't any ink in the damper, or the plastic on the damper looks puffy then replace it. There is a rubber washer in those that fail sometimes as well.

Inspect the glass below the feeder for ink or ink correction liquid remnants from previous scanned documents. Clean them out.

Try changing the cartridge.

roland SJ-740 ink not filled, how to escape this setting

If the line is only there when using the ADF (Automatic Document Feeder), you need to clean the area of glass just past the point where the paper leaves the feeder and is scanned just before it comes out again. That will be at the left end of the feeder and the glass stage. There will be white-out, dust, a marker ink, etc that is blocking the light from scanning the page at the same spot where you see the line on the copy.

Also, lift the cover on the ADF and blow it out with a can of compressed air.

try vacuum cleaning ink cartirge mechanical area maybe some dust or paper there. or change ink cartridge.

Unfortunately it sounds like the wide format printer you have will need some hardware replacement, it sounds like some part of the ink control has malfunctioned =(. Very difficult to say what you have going on, you sadly will have to call Roland to have them diagnose it. Their number is:

(800) 542-2307

WE HAVE AKODAK ESP-3 ALL IN ONE.
RAN OUT OF BLACK INK. HAVE REPLACED BLACK CARTRIDGE 2 TIMES BUT CANNOT GET BLACK TO PRINT. WHAT SHOULD I DO NEXT???

I think you need to change the tranfer belt assm.
If all the colors are smearing .

Or all of your toners are bad and leaking,
Hope this helps

You can try an Initial Fill of your ink carts. It is the next level after attempting to clean the heads. However, if this only temporarily fixes your problem, you could have a leak in the supply tubes, or the head could have failed.

Turn the epson off. Hold down the buttons [Paper Feed δ]+[Paper Feed ∇]+[Cut/Eject] and turn on the printer. This will take you into a hidden service menu. Hit the [Paper Feed ∇] button until you get to "Cleaning" then hit the [Select] button to enter that submenu. Hit the [Paper Feed ∇] again until you see "Init Fill", and then hit the [enter] button. The display will say "charging". Just wait until it is done, then turn the printer off and back on.
If you do not have enough ink in the in the carts you will be prompted to replace them. The same goes for the maintenance tank. Make sure you put the ink lever back in the lock position if you change the carts. (It will not give you an error about the ink lever being down, it just won't do anything.)