How can I fix Bernina Nova electronic 900 sewing machine?

I have a bernina nova 900 with a similar problem, when trying to sew I have to put my foot full on the peddle to make it work and then it is very fast, it works every time but I can't go slow unless I start very fast and then reduce my speed. Do you think this is the capacitor or a problem with the motor?
Thanks

Lydia
October 2013

i have a motor that will not go on when i put my foot on the peddel , do you think that my motor needs to be replace thank you franci

francis janssen in south africa
February 2012

i will go and open it and take a look at what you said , i all so have a moter that will nok at all do you think i must replace it

FRANCIS JANSSEN
February 2012

Thank you Robert
The 0.01uF/630V was indeed cracked, I measured it with a capacimeter and seem to be OK (0.017uF) but I replaced it and it works.
Probabely once the voltage increases, the characteristics of the capacitor changes.

Thank you twice Robert

Bernard (Belgium)
August 2009

There is a small condensor on the board, close to the machine front edge. It is a yellow colour, and devellops cracks along the sides with age. When faulty,the machine will not start most times. Sudden rapid pressing on the pedal will make the machine jerk into action, perhaps two times in ten depressions. I use a .01uf 630 v condensor to replace it in our 230v New Zealand system. Another common jerkey running fault comes from one of the two black three legged transistors. They are usually positioned together and are quite small. The boards are easily broken when removing the two light wire pins. Standard mechanical pedals can be fitted by a skilled mechanic, and the boards can then be discarded altogether.
Regards... mansrobe...Trademe NZ

robert
May 2009

I have the very same problem on the very same machine. With the petal pressed the motor will jerk at times. I am in the middle of attempting a repair. I have determined that the motor turns fine when connecting to line voltage. The foot control switch and rheostat is working as proven by an ohm meter. I am testing with a digital meter trying to reverse engineer this circuit should look on paper.

Al Swann
April 2009

Do yourself a big favour and get the machine into a Bernina dealer, if you blow those boards you are looking at a fortune for replacement.
ken

drivewithken
April 2009