Around the 18th of December in Seattle it started to snow and it kept snowing on and off for days. Seattle is a city that doesn’t normally get much snow, so the city has only enough plows to say they have plows and they’re doing the best that they can, but not nearly enough plows to make any kind of difference. Most of us had to walk or take the bus or just had to stay home and wait it out. UPS and the USPS slapped chains on their trucks, but FedEx did not rise to the occasion. We didn’t know early in this siege that we would not be getting any FedEx deliveries (and by the 27th no deliveries had yet to be made). But 9 days at home did give me the chance to catch up on lots of Mr. Fix-it projects.
First, I fixed the Dualit toaster (half of the elements of which have not worked for more than a year) by carefully tucking the end of the broken winding under the next loop of the heating element. Leave it to the English to build an appliance that can actually be disassembled and repaired rather than just thrown away. A replacement element is on order to make the repair permanent.
Somewhere along the way I fixed several strings of Christmas lights; each was a simply traced problem (burnt-out bulb, loose fuse).
I then debugged the treadmill which mysteriously stopped turning on. Working my way from the base with the motor, fuse, etc. up to the top section which houses the microcontroller, display, and switches, I determined that a ribbon connector that had been improperly placed during a repair early in the life of the treadmill caused the problem. Over time, it had been bent past its tolerance, breaking one of the traces. I used a bulldog paper clip to temporarily hold the broken traces together until I can get a more permanent solution in place.
Finally, I tackled the Sony DVD recorder that had an intermittent problem of the left audio channel randomly cutting out. It is only about three months old and is still under warranty but good luck finding all the receipts, sending it back to some service center who knows where, and waiting an indeterminate amount of time to get the problem fixed. Or worse, having it work when someone on the other end tried to duplicate the problem. Instead, I took the cover off, and went to work with a voltmeter to find what I was hoping would be a simple mechanical problem since the audio problem would come and go as the connector was jiggled around. As it turned out, I traced the problem to a cold solder joint on the bottom side of the main circuit board which I easily re-soldered to be nice and shiny the way a good solder connection should be. Typically, the external connectors are hand-soldered after the rest of the circuit board is manufactured by automated component-placement and wave-soldering processes. I just got unlucky, and my unit got through the test process since the problem is an intermittent one. It was easy enough for me to fix the problem, but I can only guess at the horrors that a more typical consumer would face (“sir, your cable may be bad; sir, did you check the balance on your amplifier; sir, did you try using another input on your amplifier”) in trying to get something like this fixed. Just wish me luck when I try to explain how the improper placement of a ribbon cable on a treadmill caused a failure seven or eight years later!
Otto Berkes' weblog 