PE150 Main Power Board Fix (in theory, at least...)

Since I've recently been asked about the fix that I've been promising for the last 18 months, I thought I'd share the theory. I have repaired one of my broken boards using the parts I've obtained however I've not tested it with a motor yet. For information, the repair requires the replacement of the:

• optocoupler - TLP750
• mosfet - FS3UM-9
• transistor - 2SC1740

These three items are circled in yellow on the picture below. Depending on the extent of the damage, it may also be necessary to replace the diode and zener diode (circled in pink on the picture below). Since I had the board and soldering iron out, I also replaced the capacitors on the board. Finally, I tested that the soldering was good. As soon as I have a spare motor to risk sacrificing, I'll give the repair a test....

 

 

 More soon, no doubt.

 

D



Any requests?

Even though at the moment there are hardly enough hours in the day, I've decided to invite some topic or project requests. After all, the nights are now drawing-in and my work on rebranding our estore is nearly complete. I therefore expect to have some spare time on my hands. So, if you are contemplating making some changes to your machine, investigating a fault or fixing a new part, and you'd like to see a tutorial about it on this site, feel free to drop me a line and I'll see what I can do. I've stripped these machines back to the bare case, and fully re-assembled, so no subject is beyond this site. Or you might just want me to complete the tutorial on how I deep clean my machines!

More soon, no doubt....

D

To oil or not to oil?

There is no mention of an oiling regime in either the User Manual or Service Manual for the PE150. However, on the Brother website there are two FAQs concerning oil and the PE150. In answer to the first question, "Where do I put the oil in my machine?' the recommendation is that no oil should be put in the machine. In answer to the alternative question, 'Does my machine need to be oiled?' the recommendation is 'yes', every 300 or 500 hours depending on use, and that this is a job for an authorised Brother Authorised Service Centre.

Obviously, my recommendation is to follow the official advice from Brother. On the other hand, my machines clock up 500 hours of use in less than two months and there is no way I'm paying someone else to apply a bit of oil on such a regular basis! This does, of course, mean I have to do it myself. Two questions therefore arise:

• what oil should be used; and
• which bits need oiling?

The pictures below are of the main needle assembly after being liberally oiled on a regular basis with 3-in-1 oil. Incidentally, on the side of the can of 3-in-1 there is an image of a sewing machine which I naturally took to mean that it was suitable for oiling sewing machines. Unfortunately I was quite wrong about that. As the pictures show, the main needle bar assembly has suffered from some extreme scoring. Moreover the hole in the 'presser bar holder' through which the main needle bar assembly passes has also worn into an oval shape. The effect of all this on the proper operation of the machine was devastating. In the first place, the machine would 'squeak' within a few hours of being oiled. Secondly, over time, the quality of the embroidery suffered. Finally, the needle would not collect the thread from the bobbin (as if the timing was out).

On close examination, the oversize hole in the presser bar holder meant that the needle stroke into the fabric was way off - at the needle point the play in the needle bar was about 4mm. That explained the poor quality embroidery. And during the gradual course of this wear, the actual hook on the outer rotary hook had worn away through contact with the needle. In short, using the wrong oil had caused some serious damage - the needle bar, presser bar holder and outer hook were ruined. Luckily I had some spares on a dead machine so all was not lost.

Nowadays I use a cotton bud to dab a little white lithium grease on the needle bar at the two points where it passes through the the presser bar holder. This does have the unfortunate habit of collecting lint but I clean all my machines on an almost weekly basis and the collected lint is easily removed with a fresh cotton bud. On a less frequent basis, I apply some of the same grease to the moving mechanical parts on the upper shaft assembly.