How do i set the open and closed limits on an Ellard roller garage door?

SOURCE: Craftsman Garage Opener /

door will not go down unless you hold down the inside botton.

SOURCE: Programing limits on a Grifco MK3 Garage door Operator

You can get manual from the link below

Garage door

SOURCE: Garage door won't stay closed

Check the down limit:
 If the light bulb(s) on your operator are on the front and/or back, the limit adjustment screw is on the left side of the operator (looking from the back of the operator and facing  the garage door).. If the lights are on the sides of the operator then the limit adjustment screw is on the left side (looking from the back of the operator and facing  the garage door)

SOURCE: My garage door opener won't close the garage door.

Most likely your door sensors have been bumped and are not aligned properly. Make sure they are pointed at one another and the small light on each one is lit and not blinking.

SOURCE: garage door squeak when closing

I had a similar problem and tried simlar fixes. Spraying the chain, the rollers, the track with silicon based lubricant did not good for my problem. My wife then listened carefully from where the squeak was coming. It was coming from the hinged in the actual door, the hinge like parts that allow the door to roll up. After we sprayed all of them, the sound just went back to the normal electrical / mechanical sound of the door opening and closing. I am sure our neighbors are happy too after 6 months of (very) early openings. Hope this helps.