7.5 I did find two guide stars close to M31 and one should be SAO 36618. The design of the Celestron guider is good. Adjusting the prisma and rotating it radial makes much possible. The only problem is that not all positions are comfortable for long guiding. I still can not focus the stars till a point.
Bright stars look like small comets.
Is this normal. Then the problem of the illuminated guider. Nice design but somehow the LED is to bright. So bright that I could not see the faint stars. The eyepc has an adjustable button to dim the light.