Intro: Repair a Blender
I managed to burn out my counter-top blender the other day. This was both irritating as it meant I had to mix by hand, and entirely my own fault as I was trying to cream butter and sugar together with a blender.
So how to repair a domestic appliance?
I had a reasonable selection of tools, and most important of all, access to a search engine.
This 'Ible details the steps and mis-steps which led me to a solution and is indicative rather than prescriptive. Your appliance will almost certainly be different but hopefully my journey might be helpful.
Step 1: Taking It Apart
Technically, the first step to repair was waiting for a while. There might have been a self-resetting safety mechanism inside the case, so I waited a few hours and then powered on the motor. Nothing happened, which gave me some confidence that there was an actual break somewhere.
Searching the internet for a repair manual for the product returned a couple of scam-looking sites which offered to sell the manual, but no actual information.
The underside is always a good place to start, and I found no fewer than seven deep holes there, but only three of those had screwheads visible at the bottom of them. They were easy enough to remove after which, the case separated easily, but the top could not be lifted off as the stud which drives the impeller was wider than the hole in the upper surface of the case.
Time to ask Mr Google (or Mrs Duck Duck Go, or Ms StartPage). Again the net let me down, but I did find a video on removing the stud from a different make, which recommended levering the old one off. Tried that. Failed.
Found another video for a different different make which also recommended levering the stud off, but then mentioned in passing that the stud was threaded to screw on, and that it had a left-handed thread. This was the vital clue!
Looking closely at the stud showed that it rotated clockwise (seen from above) and so a left-hand thread would have been sensible.
Re-examining the underside showed a metal fan to cool the motor, and the file blade on my Leatherman was a perfect fit to slide through the vent grille and jam the fan to prevent the motor moving. With the shaft thus secured I used a pair of pliers to grip the stud (with trepidation) turned it clockwise. IT CAME FREE, which was just about the high spot of my day.
Step 2: Examining and Testing Internal Components
With the top cover off, the first thing noticed was a small yellow block. Searching for the part number identified it as a capacitor. It didn't look to have any physical problems (distortion, holes, smoke stain) so I checked it with a meter and it looked OK. Time to push on.
There was a plastic cover over the motor, and then that was removed the two screws holding the motor in its housing were apparent. There was nothing looking damaged on the top part of the motor, so I drew it out of its housing and turned it upside down to check the rest of it.
There were two small blue disc capacitors visible, both of which were checked visually and electronically and which seemed OK.
The brushes on the motor were visible through the side, and they were also checked visually and electrically without any progress.
Then I followed the wiring to the switch and found the thing shown in the first photograph above. A bit of thinking led to "could be a fuse", which was the second time I went "whoo."
Step 3: Accessing and Testing the Fuse
To get access to the fuse required removal of the switch.
To remove the switch required access to two screws right inside the base of the casing.
To get access to those screws required removal of the control knob.
To remove the control knob, about four hands were required to bend and stress various plastic catches at the same time, which is why there is no photograph of that.
Seriously, this bit of kit was not designed for ease of maintenance.
Once the knob, screws and switch were out, there was enough access to cut through the heat-shrink tube around the fuse.
Great news, and another "whoo." It was in fact a fuse and it had a little scorch mark on the inside of the glass where it looked as if the fuse had blown.
I buzzed that out to prove that the fuse was blown, and then removed the fuse from the in-line end-caps which held it in the circuit. The type and rating of the fuse is usually etched in the metal end caps, but without an impressive macro lens you'll have to take my word for it. This claimed to be a "250V, 2A Slow-Blo". The mixer is designed to run on 240V mains, and is rated at 430watts, while the remaining wire in the fuse appeared to have been coiled before blowing, so all of those claims seemed plausible.
Time to find a replacement.
Step 4: Replace Fuse, Insulation and Case
After an afternoon of driving around, I sourced a replacement. Thank you Jaycar! (Other suppliers are available. They just don't carry 2A slow-blo)
Before fitting the fuse into the holder, I cut enough 10mm/5mm heatshrink to cover the whole assembly and slid that over the longer side wire.
Then I bolted the motor back into its housing and refitted the cover before a very quick test with the lid off ensured that things were turning.
The heatshrink was slid into position and a party candle was used (carefully) to apply enough heat to cure the sleeve. I really need to buy a heat gun.
After that, the wire was routed neatly the way it had been and the switch and knob were refitted. Then the lid went on and was screwed back into place.
A final check that there weren't any spare screws sitting around, and then I refitted the driving stud.
Power on and everything is working! Yay, that's a hundred bucks I don't have to spend.
Lessons and Learnings
If you can't find exact manuals, do a fair bit of research before getting too physical.
Have a decent stock of fuses; it will save a lot of driving.
It's always worth trying to repair something.
Don't cream butter and sugar in a blender.