My machine works fine but the LCD is blank so I can't tell when I am changing width or length.

You mean 'stitch length'? Width would be governed by the needles width

Manuals

Page 5 - Part 24 = Stitch Length Dial

https://www.manualsdir.com/manuals/719470/singer-wsl2000-ats-part-1-wsl2000-ats.html


https://www.google.com/search?q=white+superlock+2000+ats+manual+pdf

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If you have a machine capable of making a zig-zag stitch, there is a stitch width selector along with a stitch length selector. Search for a manual:

Make Model manual

Most likely the machine has seized due to old oil locking the moving parts.

Wheel on right side that controls the needle up and down is very tight...

the forward /reverse control sets the stitch length(width) the closer to neutral the smaller the stitch
full forward or full reverse is max stitch length

All machines are similar.
Push the zigzag control to begin: To control the zigzag appearance the width and length have to be changed.
Width: This is to control the width just as it says; wide.
Length: This is the length of a straight stitch. As it is made longer the length of the zigzag from one tip to the next tip will lengthen. If it is made shorter the tip to tip measurement will shorten.
This is easy to learn. Give it a try on old material.

Easiest way is to create a bar tack at one end of the buttonhole (widest stitch width and stitch length set to 0). Stitch maybe 4 or 5 stitches.
Then move needle all the way to the left, set stitch length to very short (maybe somewhere between 0 & 1), width to slightly less than half, stitch forward to the end of the buttonhole.
Then make another bar tack (as above). Move needle all the way to the right, set to less than half width, short stitch length, and stitch in REVERSE to first bar tack. To tie off, set width to 0 and length to 0 and stitch 2-3 times in place. Raise presser foot, pull gently on fabric and clip threads.

service time...either needs new screen or motherboard.

could be the motherboard or switch but the sewing machine
needs to be checked for sure

After putting on the buttonhole foot, you lower the foot, put in the size button you want into the button hole foot. Lower the button hole lever all the way (so machine does not blip) Then the machine automatically sets the length and width of the button hole...you can adjust the length and width manually by pushing the button on the top right hand part of the machine above the LED screen the top one is stich length the other is stich width....if you put the levers to the left it will be the smallest stich length or width...if to the right it will be the largest stich length or width the machine allows. But, really the machine automatically does this for you...so I don't see the need to do it.....but you can....BBill01

I have a White 1418. Here's how you do it:

1. Attach the buttonhole presser foot (should have come with your machine) and place the fabric underneath.
2. Set the stitch length knob to 0, the zigzag width knob to 5, and set the needle position to center. Sew 3-5 stitches.
3.Change the stitch length to 0.5, the zigzag width to 2, and the needle position to left. Sew to the entire length of your buttonhole.
4.Set stitch length knob to 0, zigzag width knob to 5, and needle position to center and sew about 3-5 stitches
5. Set the stitch length knob to 0.5, zigzag width to 2, and set needle position to the right. Pressing the R button (reverse button), sew up to the top stitches.
6. Remove the fabric and open the button hole with a button hole cutter.

Sounds complicated, but it's really easy. I love this machine, you just have to know how to use it!