RotaryQueen

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I found a Bernina 830 record on craigslist for $40!!! I never thought I could get one of these wonder machines on my budget. And, the plastic gears are still intact! No accessories, of course, except the case, cord, controller and zig zag foot. I made some quick bags for the cord and controller to keep them from nicking the machine.

The problem is, it only sews at top speed when the foot controller is pushed to the max. I have scouted possible causes and it could be a bad circuit board in the controller, or worn brushes in the motor. Ironically, nowhere can I find instructions on how to remove the end panel (to access the belts) or take off the cover to access the motor. I don't see any screws on either of these panels, and don't want to pry too hard on the end panel which is plastic.

Any Bernina users who have opened their machine up? Do I pry, and where? Or are there screws under the bottom panel?

hybearn8er

Bernina thirtysomethings is a group on yahoo that has lots of information on the old ones in their files.It also has a lot of helpful people as members.

Mickey2

Could be the capacitor getting old too. For the motor it's a box / cover in the back, there should be screws some where. There are usually screws for the side plate on the hand wheel side too. I have a Nova 900 and a 730 here, but I can't remember for the 830. The capacitor tends to be placed near the motor on these, but I don't know if some have one in the pedal too.

Battle Axe

I'm certainly not an expert and have only been inside Berninas limited times, but it seems like you just can't take one plastic panel (outer shell) off. They all have to come off ....in order...taking pictures of what screw goes where. Then the last one, the one you want, clicks into the other parts with extensions of their edges.

An experienced Bernina dealer might be the answer...if it were me.

Marcia

sewbizgirl

You have to remove the bottom cover in order to get to the two big screws that hold the side plate and motor on. I am away from my Bernina 830 right now, but I do remember you have to take off that bottom plate, then remove screws to take off the side panel. Then you remove the motor and slip the pulley off the belt. It's a good idea to check the motor brushes and see what they look like.

If I'm not mistaken, the foot controller is also the speed controller, and I think it's normal for the machine to go faster or slower based on how much you depress the foot control. So what you are experiencing with speed may be normal.

When I get home to my Bernina in a few days I can check it out more for you. I have that exact machine.

Mickey2

There's a button in the back of the machine near the motor, it regulates speed, two positions fast and slow. It's easy enough to find out.

RotaryQueen

Thank you sewbizgirl! That is exactly the info I needed!
This is the electronic version of 830, so no capacitor in the foot controller, and no fast/slow switch on the back as with the 730 or 707 (which I have worked with). The foot controller should regulate the motor to run slow, as it is controlled by an electronic circuit board, but there is no response at low foot pressure, only full speed at full foot pressure. Tomorrow I will check the brushes and clean the commutator. If that doesn't improve it, my next trick will be to find a replacement circuit board. I would rather not pay $90 for an after market foot controller that is said to be less sensitive than the original. I will report the results! Thanks for your help.

Robinrobin

This may be too late to be of help, or not fix your problem, but I am having the same problem. Or rather, was, until about 10 minutes ago. I was given (!) an 830 Record Electronic last weekend, and it was also only sewing at top speed, only at the very end of pressing the foot control. I had assumed it was the capicater, based on googling. I’m trying to do all the refurbish/maintenance on this myself, especially since there isn’t a Bernina shop all that close. Saw that there is an adjustment screw on the bottom of the foot control, just a small screw with a + and -. I turned it towards the - side and it stopped running completely, turned it all the way to the +, am due it is suddenly working, at all speeds. The motor is sounding a little clunky at super low speed, though. That’s how I found this post, I’m trying to figure out how to take the end cover off to get in and oil that side of the machine. It sat unused for about 20 years, uncovered except for being lowered down in a drop down sewing cabinet, in a smokers house.

RotaryQueen

The update I forgot I promised��: I got the cover off, checked the belts, commutator, brushes, and all were fine and almost new. Checked the reaction when turning the screw on the bottom of the foot control, no improvement. Took the foot control apart and checked the length/connection of the carbon points. They were fine. Based on comments I have come across, I was unusually fortunate to get it back together without breaking those very fragile points! Plugged it in with cover off and watched operation as I controlled the machine. High speed only!
I found a couple very helpful forum conversations about replacing the capacitors and resistors that made it sound doable. I looked up parts and seemed very reasonable in price. Then I got real with myself about where I would find the time to practice soldering/unsold ring and then do the touchy work on the pedal. I opted to buy a generic replacement electronic foot pedal, cut the cord from the old and rewire it. I was going to have the local "authorized" Bernina tech do the job, but he's a kid who promised to do it that evening or next morning latest. Two days later I took the machine back and bought the part from him to do it myself.
Now the machine sews slowly, but hums before starting slow. At least it's usable!
Here is link to electronics discussion if any interested. I still plan to fix it one day!
https://electronics.stackexchange.co...290-foot-pedal
https://howtomendit.com/answers.php?id=91605