The red triangle light with the "!" in it keeps flashing. I've just printed some things off but now it's not printing. Need it to print obviously..

You might have a paper jam ... For a most accurate diagnosis you might use control panel app from samsung website

With the printer on...

Open the lid
Remove the ink cartridges
Lift the print head lock lever on the left
Remove the print head
Gently clean out any ink
Gently clean the copper contacts on the back
Gently clean the print head nozzle(s) on the bottom
Make sure it's dry
Re-install the print head
Put the lock lever back in the down position
Reinstall your ink
Close the lid
Try printing again
The printer may detect that you removed/inserted ink so it may go through a print head cleaning of it's own that you need to wait to finish
If needed, power cycle the printer and then try printing again
You may need to replace the print head

My work-around for this problem is to feed paper in manually through the front. I turn the printer off and make sure all paper is out of the printer. When you turn the printer on - and the blue light stays lit (if it doesn't turn it off and wait - I've had to wait quite some time sometimes).. then manually feed 1 sheet of paper in the manual feed tray at the front. When the paper is inserted... you should be fine to print - and keep feeding paper in until you get your job. If you miss - you might need to hit the "continue" (triangle button)..
I've been trying to find out why mine locks up - and why it keeps jamming - but this is a tried and proven menthod - althought it is annoying it might help you for now.. Good luck

Hello.
Hold down the Stop/Reset Button (it has a red triangle on it) on your printer for 10 to 15 seconds until the light stops flashing.
This will disable the ink level monitoring for the empty cartridge, but be careful not to print with a completely empty cartridge, as this can burn out the print head.
Regards GM

Hello.
Hold down the Stop/Reset button for approx 10 to 15 seconds (it has a red triangle stamped on it).
This dis-ables the ink level monitoring and allows you to print.
Regards GM

Hi, try to fixed the paper cassette tray and the cover it might sensing empty paper.

is this copier plugged into a network with a server??? or just on a router with computers.... this may help in deternining your problem

I guess it FixYa didn't accept my (very long, but totally correct) solution that I took the time to type. Because I refused to "sign in".
Here's the short version. Load Paper. The same thing happened to me. I replaced the toner cartridge with a new one (because of a FLASHING red light for several weeks) after the red light went to STEADY red. But it still would not print. The paper was "out". When I'd refilled the paper-tray, it printed fine. I had just ASSUMED that the steady-red light meant toner was finally OUT. WRONG! That steady-red light had nothing-to-do with toner; it meant "you're out-of-paper". Don't get confused like I did. Refill the paper-tray. Then take that expensive NEW toner cartridge OUT, and put the OLD toner cartridge back in. And keep using the "dregs" of the toner out of the old cartridge for several more weeks. And DON'T get confused by the paper-is-out condition making that red light STEADY.

That means ATTENTION, you are either out of toner or have a paper jam.

I found just doing this one simple thing sorted the problem.

First take off the front cover. Pull the tabs on the side. Pull out the big toner and cartridge. Do you see the blue tab on the top shaped like an arrow/triangle? Slide the tab from right to left - reinsert toner close door.
Hope it works for you

JPW