I fixed my touch-lamp!
February 13th, 2011 at 8:41 pm (Electronics)
I’m delighted to report that my first soldering project is a brilliant (lit.) success. After picking up a soldering station and a coil of silver solder from Fry’s yesterday, I was all set to make my attempt at replacing the bad triac that rendered my touch-lamp useless. I’d previously desoldered the bad triac and removed it, so all I needed to do tonight was solder the new one in.
Or rather, all I needed to do was solder it in, correctly the first time. Fry’s was woefully lacking in desoldering equipment so I had no way to properly undo and cleanup any mistakes I might make. Also, Fry’s didn’t have any helping hands, so I had to find a creative way to hold the circuit board fixed while I wielded the soldering iron in one hand and the solder in the other. It turns out that two pencils, a rubber band, and a weight were sufficient.
Here is the circuit board before I began soldering:
And here is the result:
Critique: To my completely inexperienced eyes, I think I might have used a bit too much solder. It was a little tricky to get my soldering iron’s “screwdriver” tip positioned to heat precisely one of those posts at a time; a smaller tip would have been easier, I think. Also, by all reports a good solder job should leave you with very shiny clean connections — but these dulled when they cooled so I’m not sure if there were impurities or I didn’t keep it hot enough or some other issue. So it was with great apprehension that I plugged the lamp in, but voila!
You can’t tell from this static image, but it DOES work, flipping between off-low-medium-high brightness when you touch any metal part of the lamp. Yowza!
Here’s the other side of the circuit board, with the new triac clearly visible (and correctly oriented, or the lamp wouldn’t have worked):
I know that you generally clip the wire ends of components after soldering them in, but the triac’s ends were pretty thick so I just left them there. To anyone with more experience, would you clip these as you would resistor wires?
Replacement triac: $1.19
Soldering station: $39.99
Silver solder package: $3.99
Sweet, sweet success at something I’ve never done before: Priceless
What I Learned Today » Blog Archive » Desoldering a bad triac said,
February 13, 2011 at 8:42 pm
[…] I have successfully fixed the lamp! Previous: Glass isn’t just SiO2 Next: Multiplication […]
What I Learned Today » Blog Archive » Why my touch-lamp won’t turn off said,
February 13, 2011 at 8:45 pm
[…] (Feb. 13, 2011): I have successfully fixed the lamp! Thanks to Cakky_blue, below, who suggested exactly the right fix. Previous: Introduction to […]
Evan said,
February 13, 2011 at 9:57 pm
Isn’t that just awesome? There’s something so much more viscerally satisfying about making a physical object work than code, often, I think. Or maybe it’s just because we do it so infrequently.
There’s definitely something magical about your first electronic circuit. Congrats!
jim said,
February 14, 2011 at 12:01 am
Congratulations! It’s so much more viscerally satisfying fixing things than writing product roadmaps (since I don’t code and want to play, too).
Tyestin said,
February 14, 2011 at 9:28 am
Huzzah!
Congratulations! :)
Scott Van Essen said,
February 15, 2011 at 9:00 am
Congratulations. Always satisfying to fix things with your two hands and hot molten metal.
I’m not sure about the composition of silver solder, but it’s likely that due to RoHS, your solder is lead free, which would account for its lack of luster.
Kiri said,
February 15, 2011 at 9:36 am
Yes, it *is* lead free, good guess! If that accounts for its dullness, I’ll take it. :)
Katie said,
February 15, 2011 at 1:03 pm
Congratulations, Kiri! That’s great! Even if you could go buy a new *insert name of object here*, it’s such a great feeling to fix it yourself, and be able to use something that YOU had a hand in facilitating its function! :)
Teresa said,
March 20, 2011 at 12:23 am
That’s awesome. My touch lamp did the same thing. Although I am very tempted to fix it like you did, I think I will just go and find a new one since the one I bought (which looks exactly like the one you fixed) only cost $4.95 on a closeout at Walmart. :-)
a said,
January 5, 2013 at 10:50 am
hey, your instructions are awesome! I had the same problem. I ordered the same triac as you and I just successfully desoldered it! yay! I see yours also has a little tab sticking out so it doesn’t fit flatly in the circuit board. Did you just not worry about this? Thanks for this page!
Rob Tatman said,
March 8, 2013 at 7:24 am
Hey Kiri,
Thanks to your instructions I now have a working touch lamp and, more importantly, a lovely warm glow of satisfaction from having repaired something myself and learned a few new things along the way :-)
Thank you thank you for sharing!
Cheers, Rob
Oliver said,
August 26, 2014 at 5:10 am
Hi Kiri,
Did you end up following this guide on Lets Fix It or not?
Cheers, Oliver
Ralph Mills said,
March 30, 2015 at 11:56 am
Thanks,
I used your pages to explain to my 82 year old mother that it WASN’T the type of bulb I replaced her blown one with that caused her lamp to stay on.
The BT139 TRIAC I ordered arrived and I “fixed” her lamp within 30 minutes (would have been quicker but I misplaced my “Solder-Wick” and had to use the Desolder “sucker” several times to remove the bad triac.)
Ralph
P.S. I miss my local Radio Shack…
Ke said,
October 25, 2015 at 10:37 am
Love your pencil ‘tweezers’ … very clever!
I have to replace the Triac on one of my lamps and just wanted to say that I first ordered a complete module before even opening it thinking it would be less hassle and I wasn’t sure whether the components inside would be accessible.
As it turned out, the item I received used very poor quality components (especially the capacitors connected to the touch terminal which were not Class-Y mains rated) which rendered the unit unsafe in my opinion.
I ordered the Triac now instead, which I should really have done from the start seeing that I am an electronics engineer by training.
Britt said,
December 9, 2016 at 7:52 pm
Super bummed. My lamp is nearly identical to yours (different pattern on the glass) & it just did that bright flash you mentioned. I tried 2 different new bulbs and my lamp was stuck “on” .
Thanks for the info; now I won’t go looking for some magic light bulb, but I have zero chance of fixing it myself. It’s not like it was some special heirloom or anything but it was really convenient for reading in bed. Oh well