Sewing machine stepper driver / motor fault finding ...( solved awaiting testing !)

[granddad]

My wife's beloved 25 year old Brother sewing machine ( Super Galaxie II ), has started to play up. intermittently the stepper that feeds the upper thread , just stops ( held ) and consequently the thread breaks, Seems to be failing after prolonged use so may be thermal problem... it is a 6 wire motor , the driver is a SLA7024M , I have checked for poor joints , loose connections , but still failing Testing is difficult. it could be the motor , or the driver IC or a long shot the controller I could get a new IC , but a big job to get to the board. Testing is difficult .... Any advice , knowledge, suggestions very much appreciated.

 

[ronsimpson]

If I came home and my wife found this:

It would be the end of me.

 

[alec_t]

it could be the motor , or the driver IC or a long shot the controller

Another long shot - motor bearing seizure from lack of or dried out lubricant.

 

[KevinW]

Have you tried a sewing forum?
**broken link removed**
My machine for leather work doesn't feed thread it gets pulled through by the needle.

 

[granddad]

Thanks Alec, Kevin and Ron , Day 2 .... The reason the stepper had hold of the thread ... it was waiting for the upper thread tension sensor ( buried deep in the guts ) to activate , it couldn't because of a single loose thread blocking the gap .... just a clean and a blow and hopefully we are good again, you never know with these things .