Monday, 7 November 2011

A little bit on the side....

Not had much time lately to spend on my project machine or this blog.

And then on Sunday night, the first reasonably chilly night of the year, my boiler packed up.

In fact, to be more precise, there was no spark at the electrodes over the gas burner and so the damn thing would not light. Now, being the inquisitive sort, I couldn't help having a poke around. I quickly identified that tapping underneath the tray containing the PCBs whilst the boiler was going through its lighting cycle resulted in a spark and flame and a lit boiler. On the other hand, this was the only way to get the boiler to light, whether for hot water or heating. Needless to say, the house was freezing cold this morning when I woke up.

On inspection through the window into the combustion chamber, the electrodes do look like they're past their best: the gap between them is, according to the manufacturer, supposed to be 4mm. The ends of the electrodes look burnt away and the gap looks at least 6mm so I've ordered a new pair today.

That doesn't explain why the boiler wasn't even trying to light, however. So, bearing in mind my technique for getting it to light (see above), I decided there might be a fault on the ignition PCB.

A bit of googling later and it turns out that this particular PCB is known to have problems. The PCB is made by Honeywell (GC E83-142) and is used in a number of boilers made by different manufacturers (for example Ideal (part no. 172548) or Biasi (part no. BI1305101), same part but different price!). Perhaps more interestingly was the number of firms offering 'repaired' PCBs on an exchange basis for about half the price of a new board.

Tonight I removed the PCB. The photos below show heat damage on the board around the 16KO and 10KO resistors. In fact, the heat seems to have dissolved the original solder away and the resistors were 'rocking' on the board. This probably explains why the boiler did start when I gave the underside of the PCB tray a knock - it was enough to shake those poor resistors into action!

So, I popped out my trusty soldering iron and after cleaning off the old, burnt varnish, applied some fresh solder at the relevant points. A quick visual check over the rest of the PCB didn't reveal any other obvious problems so I refitted the board and switched the boiler on. That was a couple of hours ago and the boiler has been fine since. Toasty.

Tomorrow I think I'll get some replacement resistors and do a proper repair job. This will complement the new electrodes (the Ideal part numbers for which are, incidentally, 172532 and 172533 (GC E83-126 and E83-127)).

More soon, no doubt...

Monday, 17 October 2011

Buying spare parts...

I didn't get chance to finish the cleaning tutorial today however I have been asked about where to buy spares. I get my original Brother spares from Bedford Sewing & Knitting (click the name to open their website and note that you will need to call them with your requirements). I use BSK as they are in the UK, as am I, but in my quest for cheaper spares I've found a few places elsewhere in the world although they do not, apparently, supply to the UK.

So, for the USA, you've got UED and BOS and for Europe I found Convena. No doubt there are others but these sites have online searchable catalogues (by manufacturer part number) and price lists.

Having said all that, I'm determined to find a cheaper way to fix these machines. For example, the £60 replacement motor for the PE150 is made by Johnson Motors (minus the PCB assembly, which is serviceable for a few pence, but that's a tutorial for another day). This is the current incarnation of the motor and I expect, if it could be bought on its own, would be less than £10 but can I find a supplier who will let me buy just a couple of units? No - minimum order is 5000....

More soon, no doubt.

Saturday, 15 October 2011

Google +1 button

I'll be adding a new page this weekend which covers "A Good Clean". Until I do, I've been reading about the Google +1 button which appears after each post. You can read about it here. But basically, if you like any of the content on this blog, simply click the +1 button. Easy!

Thursday, 25 August 2011

Brother PE150 replacement power board...

... has arrived. It's 'new old stock' circa 2007 so I wasn't hopefull of identifying any of the components on it. However, having done a quick search courtesy of Google I've found the datasheet for the main power transformer which is made by a different manufacturer to the ones on my existing broken power boards.

More soon, no doubt...

Wednesday, 24 August 2011

New PE150 fix coming very soon....

I have a new PE150 power board on the way from Brother. I'm rather hoping that it will be brand new and not just 'new old stock', particularly as it has a new part number. If so, then before fitting it I'll be doing some comparisons with an old (but working) board, and also collecting the relevant data sheets for all the components on the board. It may be that I can actually start repairing my old broken boards too.

Sunday, 21 August 2011

New tutorial completed!

The 'Check and adjust the timing' tutorial is now complete. Click here to view the tutorial or click the link in the left-hand margin.

For the benefit of internet search engines, the tutorial explains how to:
  • adjust the timing on a Brother PE100
  • adjust the timing on a Brother PE150
  • adjust the timing on a Brother PE170
  • adjust the timing on a Brother PE180
  • adjust the timing on a Brother PE190
  • adjust the timing on a Brother PE200

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.

Saturday, 20 August 2011

New tutorial completed!

Well, about 95% done: Click here to view the Main board, power board and motor removal tutorial or follow the link in the left-hand margin

Friday, 19 August 2011

First you get "Check if thread is entangled. Check if needle is bent"...

.... and then the machine won't embroider. You do indeed "Check if thread is entangled. Check if needle is bent" but everything seems ok. So, what's the problem?

In short, the motor has blown. Specficially, the two induction coils on the PCB attached to the motor. In this picture they are the little brown capsules with stripes:

On your motor the coils are most likely green (but with the same pattern of stripes indicating 10 microhenries).

So, why does this happen and can it be fixed?

Well, I have nothing more than a theory at the moment but a couple of points are without doubt. First, the induction coils don't simply wear out. In other words, something caused them to go pop. The coils can be replaced by soldering two fresh ones on the board but without something else, they are likely to go pop again. Second, and almost certainly, the resistance across the main terminals of the motor will be far less than the figure of 400 - 800ohms specified in the Brother Service Manual. My theory, at present, is that with wear the resistance in the motor reduces which causes some sort of spike in the power going to the motor and this fries the coils. If this has happened (and it or something has happened in three of my machines), simply replacing the coils (about 10p) or fitting a new motor (about £65) will not sort the problem. Alas, a new power board will also be required (about £160).

For more on this please take a look at the tutorial on Main Board, power board and motor removal.

Quick update that I've been meaning to put on here for a while - if you get the "Check if thread is entangled. Check if needle is bent" message but your bobbin winder is still working, then your motor (and main board) are fine. You just need to look a bit closer at your machine as the chances are your thread is entangled or your needle is bent..... or the magic eye on the main shaft has failed....

New tutorial completed!

The 'Take it apart' tutorial is complete. Click here to view or follow the link in the left-hand margin.

Thursday, 18 August 2011

The Clinic is launched...

... but is still under construction. For the future expect step by step guides with photos and, if I have the time, videos. If there are any specific topics you want covering just drop me a line and I'll see what I can do.