Samsung SCX-4623FW - I can scan or print, but not both

[SiKing]

I am running Linux Mint 17.3 == 14.04.1 LTS, Trusty Tahr.
My MFP is Samsung SCX-4623FW connected via USB.

Using only the drivers that come with the distro - I do not know how to tell which ones they are - the printer is automatically detected and prints perfectly fine. However, the scanner does not work at all. Simple Scan detects the scanner (correct "Scan Source"), but after clicking Scan it reports only "Failed to scan".

I tried installing the Samsung drivers. I first tried version suld-driver-4.00.39, and then version suld-driver-4.00.36 (which is listed as minimum for my scanner). With either of these drivers I can scan, but not print.
During installation I was asked which users I want to add to the "lp" group - I added every user on my system.
The administrator user - the one that I used  to install the driver - can scan in colour, but all other users can only scan in black and white. This is using Simple Scan.
Printing is completely hosed! I have an option to "Print Test Page" or "Print Self-Test". The self-test prints out a page that says "If you can read this, you are using the wrong driver for your printer." :( The test page just prints gibberish.

[bchemnet]

You can try any version starting with 3.00.65, including the driver2 options.  The 4.00.36 is just the last time an update seems to have directly targeted this printer.  Based on what you are describing, I suspect the latest driver2 is probably your best bet.

[SiKing]

I tried suld-driver2-1.00.36 (the latest available), and I am back to my original situation: print works, scan does not. The only new thing is that in Simple Scan, when selecting a scanner in Properties, my scanner now appears twice. I tried both; neither can scan.

How can I tell which driver I am using - the one that came with my distro, or the one that I just installed from suldr?
I tried to get this to work first using sane. Do I need to uninstall / undo everything I did there?

[bchemnet]

To tell which driver you are using for printing, you probably have a "Printing" or similar option on a Systems Tool menu.  (If not, you can access it by typing "system-config-printer" in a terminal.  In the event that is not installed, you can install the package the normal way.)  Then select the printer, go to Printer menu -> Properties, and look at "Make and Model".  If it starts with "Samsung Series..." it is the Samsung driver.  You can change the model here as well.

As far as the scanning, you will just need to keep trying different drivers until you find one that seems to work for both.  That is why there are so many drivers available in this repository.

[SiKing]

So now I am up to:
- printing works
- scanning works half the time, some of the time
I tried scanning using XSane. Scanning first time fails every time. Scanning subsequent times works fine. XSane reminds me of the days of GIMP: way to much is going on.
This is a computer for my (elderly) parents. Simple Scan would be a much more appropriate applications for them. Unfortunately, Simple Scan fails every time.
Any ideas?

[bchemnet]

Unfortunately I cannot offer any additional advice beyond what is posted on these forums and the website.  I don't have any personal experience relevant to this situation, and have never used Simple Scan.

[SiKing]

I appreciate all the help you have given! At least I got it this far.
Thank You.

[vasia]

My MFP is Samsung SCX-4623FW connected via USB.

Do you mean this model? http://manualsbrain.com/en/manuals/113969/