I picked up a Dell/Altec-Lansing ADA885 sound system for cheap, not expecting it to work at all since the plastic on the bottom of the subwoofer was distorted from melting. The idea was to build my own system if this one wasn't repairable.
Fortunately, it seems it is. There are two amplifier ICs I presume to be for the four satellite speakers. They are part number TDA7265 and sell for about $5 each.
The weird thing, though, is that these amplifiers are supposed to be protected from shorts and such. And they're actively cooled by the air at the subwoofer port blowing over the thick aluminum heatsink. I wonder what happened? This has shades of the receiver I tried to fix back in 1998. While I was able to replace the STK0050 amp packs on that, it never worked right afterward and had nasty clipping. I know more now than I did back then, however.
Basically, I can spare the money to replace the amplifiers without blinking an eye, but if the work required amounts to much more than that, this system is going to get a retrofit job with better amplifier modules that aren't going to fit inside the case.
Friday, August 21, 2009
Monday, August 10, 2009
No Kid Should Be Subjected To That...
My wife and I have gathered quite a collection of Disney movies. The classics we own are simply timeless, except for one thing--the damned ads preceding the movie.
Today, I put The Little Mermaid on for our daughter to watch before being taken to daycare. This version of the tape has the lady who voices Ariel conversing with two fish and waxing all infomercial for half an hour about new Disney stuff. Well, new for 1998 anyway. Yeah, 11+ years ago.
I'm solving this problem. Not only are the tapes going to wear out at the rate we're going, but VCRs are of a rather limited lifespan. I've already licensed Little Mermaid and such so I'm downloading files of each one and putting them on a specialized computer where our kid can watch the movies without the rewind time or ads. Ads in a movie theater I understand. They don't belong on the home version. If the MPAA has a problem with this approach when I've already bought the tape, they can eat shit. No kid should have to watch ads when they want to watch the movie.
Today, I put The Little Mermaid on for our daughter to watch before being taken to daycare. This version of the tape has the lady who voices Ariel conversing with two fish and waxing all infomercial for half an hour about new Disney stuff. Well, new for 1998 anyway. Yeah, 11+ years ago.
I'm solving this problem. Not only are the tapes going to wear out at the rate we're going, but VCRs are of a rather limited lifespan. I've already licensed Little Mermaid and such so I'm downloading files of each one and putting them on a specialized computer where our kid can watch the movies without the rewind time or ads. Ads in a movie theater I understand. They don't belong on the home version. If the MPAA has a problem with this approach when I've already bought the tape, they can eat shit. No kid should have to watch ads when they want to watch the movie.
Sunday, August 9, 2009
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.
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.
Saturday, August 1, 2009
A New Record
Last night I completed the biggest hack I've ever done.
Some months ago, I bought an industrial 32" LCD monitor from the Logan DI store. They had priced it at $80, but I found that it didn't actually work. While it would display a frame when turned on, the image didn't move at all. I opened it up at the store to have a look and found that the controller board had been messed with at some point by a tech who didn't have a clue and probably used a $2 Radio Shack soldering iron. Since it didn't work, they were going to trash it but I offered $20 in the name of just having the panel for later use since I knew it worked well enough.
And then it got in my way and would continue to do so for a long time until yesterday.
Thursday night, I spied a flat TV sitting behind the local home theater store and wondered if they would let me have it. Yesterday I went in and asked and was allowed to take it. Vizio 37" with a cracked panel and the coax jack ripped out. No tuner love, but there were plenty of inputs to make the project worthwhile.
I plugged the set in at home to see if it would light up and it did, with the interesting patterns that only come from a cracked panel. At least the guts still worked and the viewing angle of the panel had me thinking S-IPS technology. Maybe an LG/Philips panel?
I removed the back panel and had a look around. The LCD panel looked like a larger version of the 32" panel and the power supply and inverter boards were LG branded. LG/Philips panel. Had to be and it was.
So it was time to check pinouts to see if I could hack the two together. The connectors were the same type on the inverters, but the 37" panel had 14 pins on one board where the same had 12 on the 32" panel. Fortunately, reverse-engineering was cake. The 37" panel inverters had a pinout silk-screened onto the boards and, while the 32" panel didn't, it was real easy to figure out because the boards the cable connected to did have silkscreened pinouts.
It took me half an hour to pull and reorganize the pins to the inverters, double-checking my work, but they looked production-grade when I was done. The signal cable for the display was a different matter. It didn't have enough conductors on the controller end so I thought I'd have to use the panel-side board from the 37" panel to make it work. No. After turning the display on and seeing no change then plugging the inverters and seeing a bright blue LED light and then dim on the main inverter board with no backlight action, I figured I'd go back to the original panel-side board and just use the 37" controller-to-panel cable and see what happened.
It would seem that the system was designed to take several configurations because I was startled when it fired up to a blue screen after I plugged the inverter with the power still on. Slight spark from the 24V line and slight flicker from the blue LED.
Blue screen means nothing. I hit the menu button (it was silkscreened as menu, but it was the source switch button) and the OSD came up. The hack worked, but what about taking a signal? Easy was to check. I hooked my Xbox 360 up to the VGA input and went for it.
It worked. I played Saints Row 2 for a couple of minutes to check response time. No problems, solid response. Excellent.
Now how the hell am I going to put it in a case? My work is half done.
Some months ago, I bought an industrial 32" LCD monitor from the Logan DI store. They had priced it at $80, but I found that it didn't actually work. While it would display a frame when turned on, the image didn't move at all. I opened it up at the store to have a look and found that the controller board had been messed with at some point by a tech who didn't have a clue and probably used a $2 Radio Shack soldering iron. Since it didn't work, they were going to trash it but I offered $20 in the name of just having the panel for later use since I knew it worked well enough.
And then it got in my way and would continue to do so for a long time until yesterday.
Thursday night, I spied a flat TV sitting behind the local home theater store and wondered if they would let me have it. Yesterday I went in and asked and was allowed to take it. Vizio 37" with a cracked panel and the coax jack ripped out. No tuner love, but there were plenty of inputs to make the project worthwhile.
I plugged the set in at home to see if it would light up and it did, with the interesting patterns that only come from a cracked panel. At least the guts still worked and the viewing angle of the panel had me thinking S-IPS technology. Maybe an LG/Philips panel?
I removed the back panel and had a look around. The LCD panel looked like a larger version of the 32" panel and the power supply and inverter boards were LG branded. LG/Philips panel. Had to be and it was.
So it was time to check pinouts to see if I could hack the two together. The connectors were the same type on the inverters, but the 37" panel had 14 pins on one board where the same had 12 on the 32" panel. Fortunately, reverse-engineering was cake. The 37" panel inverters had a pinout silk-screened onto the boards and, while the 32" panel didn't, it was real easy to figure out because the boards the cable connected to did have silkscreened pinouts.
It took me half an hour to pull and reorganize the pins to the inverters, double-checking my work, but they looked production-grade when I was done. The signal cable for the display was a different matter. It didn't have enough conductors on the controller end so I thought I'd have to use the panel-side board from the 37" panel to make it work. No. After turning the display on and seeing no change then plugging the inverters and seeing a bright blue LED light and then dim on the main inverter board with no backlight action, I figured I'd go back to the original panel-side board and just use the 37" controller-to-panel cable and see what happened.
It would seem that the system was designed to take several configurations because I was startled when it fired up to a blue screen after I plugged the inverter with the power still on. Slight spark from the 24V line and slight flicker from the blue LED.
Blue screen means nothing. I hit the menu button (it was silkscreened as menu, but it was the source switch button) and the OSD came up. The hack worked, but what about taking a signal? Easy was to check. I hooked my Xbox 360 up to the VGA input and went for it.
It worked. I played Saints Row 2 for a couple of minutes to check response time. No problems, solid response. Excellent.
Now how the hell am I going to put it in a case? My work is half done.
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