Hi Hero999,

One leg (Green/Yellow wire) seems to go to pin 9, while the second leg (black) goes to one the primary coil of what I believe is an isolation transformer, and the third leg (black) goes to the secondary coil as well as to a diode and to one of the two black box components in the centre of the board, markings BBC CS1 05do4 517A.

Not sure if the above description helps much.

Pete

 

The coil looks like a filter rather than a transformer.

Where does pin 9 go? The wiring diagram in the picture you've posted doesn't say.

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Hi Hero999,

Not entirely sure where pin 9 goes, the diagram on the lid looks like a switch, which I'm guessing is the lever switch on the sewing machine that causes a change of sewing direction from forwatd to reverse.

I will seeif I can work out what switch this is later on by opening up the sewing machine a little more.

Cheers,

Pete

 

Hello all,

I've had a look around the local electronic stores and can't locate the failed part.

So I have decided that I will make one up out of three separate capacitors of the nearest values I can find.

Am I correct in thinking that the wiring arrangement will be as follows to make the equivalent.
------------0.1uF
+--------------||--------+
|--------------||--------|
|--3300pF--- 3300pF-----|
|---||-----+---||--------|
|----------|-------------|
o----------o-------------o

All capacitors to be rated over 250V.
I assume that the outer two legs will be the black legs on the failed component and the centre one will be the green/yellow leg. Does this sound correct? Does anyone have a data sheet for the failed component that they could send through? I couldn't find anything on the net for any of the numbers stamped on the case.

I have attached another photo of the failed component that shows a three leg capacitor like symbol, in case this helps. Also, what is the meaning of Y=gn/ge ?



Thanks for any help on this.

Pete

 

Yes the middle leg goes in-between the two 3300pF capacitors.

Don't use any old capacitors, for safety reasons the 100nF capacitor needs to be an X-rated capacitor (don't wory not a p0rno ;D, it's a resistance to over-voltage) and the 3300pF capacitors need to be Y-rated.

X-rated capacitors are classified as safe to be connected across the mains and Y-rated capacitors are classified as safe to be connected from mains to earth or an exposed metal surface. There's different ratings, X1, X2 and X3 and Y1, Y2 and Y2, I can't remember what they mean (use Google if you want to find out) but X2 and Y2 are standard ratings so go for them.

__________________

I do not answer private messages asking for help because no one else can: benefit from advice I may give or correct me if I'm wrong.

Please ask on the open forum if you have a question and I'll be happy to help, if I know the answer.

 

would it be possible to look at the traces on the other side and just rebuild the thing entirely with new components? or at least figure out what the output is like and emulate it with something

 

Thanks again Hero999

I wasn't aware that the " X & Y" designations had significant meaning with regards to rating.

I'll start hunting these capacitors down today. My wife is keen to have the sewing machine working again.

Cheers,

Pete