A Case of Mischief

The hacked and homebrewed HDTV is now mounted in a proper case that blows the original out of the water. It's not complete, but it's very close

I had wanted to use the industrial steel case, but didn't really like the idea of sticking new standoffs for the new boards on the case. I didn't have to. Soon after the working model stage was completed, I realized that the mezzanine panel for the Vizio boards could be modified to work, leaving less work to be done, overall, than adding standoffs to the case.

I burned through a full pack of cutoff wheels for my aging Dremel while modifying the mezzanine for attachment to the industrial casing, but it worked. I found that my cheap Chinese drill bits with the "Titanium Nitride" coating would actually drill through steel reasonably well. Screw tabs were bent flat or cut off as needed while an entire strip of the steel mezzanine consumed the bulk of the Dremel wheels in the name of making the mezzanine lay flat against the case by evening it out to match the sides. The top was left full-size with the screw tabs bent flat to allow the mezzanine to rest on top of the case with a couple of screws in the flattened tabs to keep it secure. Two screws through the mounting holes for the original LCD module secure the mezzanine to the case.

While I had the boards out for the mezzanine modification, I decided I'd try to fix the tuner input jack. Upon popping the lid of the tuner module, I saw that the jack's signal lead had been torn from the tuner's circuit board but could be soldered easily with the right iron. An inductor had suffered the same fate at one end of it, but this was easy to fix. The jack required re-shaping the steel case of the tuner to allow re-insertion, then bending the steel back over the jack and possible soldering the jack in place around the neck. I had never done this at home and remember how much of a pain it was getting the back-EMF capacitors soldered to the steel-cased motor of an RC car back when I was a kid and I didn't fare too well ten years after that, either. Well, I had a Radio Shack iron the first time and a Tenma the next. Ten more years after that last attempt, it was all about Hakko.

The funny thing is I'm still using the same roll of solder I bought back in 1997, the very same solder I used during my second attempt at soldering to what amounts to a huge heatsink. It wasn't the solder or my technique that was to blame, it was the inadequate 30W Radio Shack iron the first time and the 60W Tenma iron's indirect coupling the second. The Hakko, with the heating element inside the tip, kept the heat on without fail and I was able to run a bead of solder all the way around the jack outside the tuner module and half of the inside. The signal lead was soldered within seconds afterward. 22 analog channels and 34 digital channels were my reward. While the analog channels were kind of weird in the upper range, which I guess is due to the inductors not being tuned right anymore, digital was perfect.

Next, there was the issue of a TV stand. While the mezzanine I had modified was equipped with mounting holes for the standard wall mounts and was secured well enough for wall mounting of the mass, I didn't want to buy a wall mount so I had to add a foot. The Vizio TV had one, but using it would require a lot of cutting to get the piece of the casing down to size for the eight mounting screws to drive into. I used my Leatherman's saw blade for that. It was a noisy job, but it worked. With more holes drilled, I was able to attach the foot. While I had thought the center of gravity would make the set front-heavy and prone to toppling, this was not going to be a problem.

Once the foot was added, more loud work with the saw converted the back cover of the Vizio set to a cover for the high-voltage components of the homebrew one. While it doesn't completely prevent entry, it's not meant to and has very good airflow so the guts stay cool. The logic board has a steel cover over it, but the power supply only has the plastic. I haven't found the steel cover for that yet. As a sidenote, I added a heatsink to the main processor of the logic board. There were two huge BGAs on the board, but the one with holes around it for cooling system mounting got the heatsink.

The work is about 90% done. The last part of this project involves creating a new power status indicator, modifying the speakers for permanent attachment, and mounting the control buttons and remote control receiver. There's a side-mounted Composite video input jack I could add to this version, but I don't know if it will fit the way I want. Once that's all done, I create a front faceplate and covers for the speakers, which will stick out about half an inch beyond the faceplate due to the way they are mounted. For now, however, I just use it.

I gave my wife an Xbox 360 for her birthday and we played Saints Row 2 for about twenty hours total over the weekend and had the TV going on various channels for another ten or so whether watching or not. It's safe to say it works and should work for a long time.