Nov 262017
 

Yesterday, I went grocery shopping.

I came home with groceries and a TV.

You see, Loblaws was selling cheap 32″ smart TVs at the checkout counter. Only 150 dollars (Canadian), and they even paid the sales tax.

We were in need of a TV. The TV that we have in the bedroom (rarely used, but good to have; it’d have been nice earlier this month, when I spent a few extra hours in bed on account of feeling miserably sick) is old, useless and broken. Useless because it’s an analog TV, and there is no analog service anymore, nor do we have an extra settop box for upstairs. And broken because… well, even when it was still actively in use, we needed to whack it every so often, as after it warmed up a little, its picture became elongated and discolored… but a good, well-aimed whack fixed it. Lately though, the picture was permanently distorted and in addition, the TV made a horrible, rattling, buzzing sound (and no, it didn’t come from its speakers.)

Anyhow, we now have a new TV in the bedroom. It picks up OTA digital channels just fine using a small antenna, and it works well with Netflix and YouTube. Perfect. And I managed to haul the old TV downstairs this morning. (It’s incredible just how heavy these larger old CRT televisions are.)

Before throwing it out, I decided to open it up. Who knows, maybe I can fix it and in that case, it can still have a second life at the Salvation Army or whatever. The later it becomes landfill, the better for all of us. So I decided to check this old beast’s innards. Which, in case anyone is wondering, looks like this (yes, I took several pictures just in case I disconnect something that needs to be reconnected the right way):

After removing the back cover and then vacuuming out a few pounds of accumulated dust, I powered it on, listening for the buzz. I also looked at the circuit board using my IR camera. My attention was quickly drawn to the left side, where there are some rather hot parts, but that turned out to be a bit of a red herring: the hottest part is a high-wattage resistor that is meant to shed a lot of heat. Next to it though… what I thought was an inductor turned out to be a relay. And that’s what appears to be rattling!

I checked online. Surprisingly, this is a standard part, not model-specific, still being sold. But the first price I saw was something like $12.50 US plus shipping. Way too much to invest into a 23 year old CRT television set. But then… I found an offer from China for the princely sum of 75 US cents, plus 35 cents shipping. $1.10 in total. Of course I ordered it.

So now I wait. When the part arrives, I’ll attempt surgery. If it fixes the TV, we’ll find a good home for it. If not… landfill, landfill, here we come.

Incidentally, this television set was assembled in Canada. How about that. I don’t think there are many television sets assembled in Canada these days.

 Posted by at 10:45 pm
Oct 142015
 

I finished this weeks ago but never had the time to post. My previous attempt to hack a Rogers cable decoder was only partially successful, so I gave it another try, with better results.

By “hack”, I don’t mean illegally obtaining cable signals or anything like. I was simply looking for a way to get composite video and stereo audio out of the “free” cable boxes that Rogers provides, as opposed to just a plain RF signal on channel 3. The reason is pretty mundane: I’ve been using a dual-tuner TV card in my computer for years, which allowed me to record one program while watching another. The transition by Rogers to full digital cable messed this up: the TV card has only one RF input, so it is impossible to attach two decoders that could supply two signals simultaneously. But the TV card does have two independent composite video inputs. So if only the decoders had the corresponding output…

Well, they do, sort of: the only problem was that the audio was an undecoded (multiplexed) stereo signal. To decode it, I first built a standard stereo decoder circuit, but that was before I learned that the NTSC standard for stereo also includes noise suppression.

Hence my second attempt, using an appropriate chip.

Once again, I used a custom printed circuit board of my own design, and once again, it worked like a charm. The only fly in the ointment is that this larger board no longer fits inside the original decoder casing without some “plastic surgery”; so chances are that if it ever comes to returning these boxes to Rogers, I’ll be paying for them instead. Oh well.

 Posted by at 12:38 pm
Aug 062015
 

Here are nearly all the parts from a recently failed fluorescent bulb, which I disassembled:

Most of these parts are perfectly good, mostly generic electronic components that often end up in the trash. All because of these:

Yes, a rotting electrolytic capacitor. The Great Capacitor Plague is supposedly a thing of the past, but bad capacitors still show up quite often. One cannot help but wonder about the possibility that this is not altogether accidental… after all, more frequent replacement of these supposedly long-lasting bulbs means more profit to manufacturers.

 Posted by at 12:09 pm
Feb 172015
 

Today, I successfully hacked one of my Rogers cable decoder boxes. No, not to do anything illegal, just to get composite video and demultiplexed stereo audio out of them, to make them more usable with the dual-tuner TV card that is in my desktop workstation.

rog-decoder-8

This is the first time ever that I used the services of a custom printed circuit board manufacturer. My design worked on the first try. I am mighty proud of myself.

 Posted by at 7:57 pm