I've connected the probe to the probe adjust signal but all I get is a flat line+ no signal+ or a sharp spike with no square wave. Why?

I've connected the probe to the probe adjust signal but all I get is a flat line+ no signal+ or a sharp spike with no square wave. Why?

If you are using the retractable hook tip on the end of the probe, try pressing the tip on very hard. A design change was made to the retractable hook tip to keep it from coming off easily, but this also makes it more difficult to press on securely. Once the retractable hook tip is securely pressed into place, the probe should work properly.