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Scrounging an old DirecTV receiver

DTVRcvrOpen Many of you may be upgrading to HD receivers for your DirecTV systems. The installers will take away your old standard def receiver when they do the upgrade but they do not have to. Tell them you want to keep it and scrounge out useful parts.

Note: You will need to get the correct sized Torx bit┬áto remove the screws. These “security” screw bits are available at just about any place you can buy screw drivers.

The first part you want to get is the 250GB hard disk. This drive is a simple IDE drive you can use in your PC projects. Just reformat it. I have already removed the drive from the pictured unit. There are a few other interesting parts you might want to scrounge as well. You can see what I collected in the full article after the jump.

DTVRcvrBoardsAfter removing the hard disk and all the boards I had a pile as shown here. There are a few boards behind the front panel so don’t forget to tear that apart.

There are two main boards in the enclosure. The main board with the CPU and video processing and a power supply board.

Power Supply
One is a nice power supply that you can reuse as is. The specs taken from a label show +3.3VDC @ 6.8Amps – 5.0VDC @ 3.3Amps – 7.5VDC @ 2.3Amps – 12VDC @ 2.4Amps – 32VDC @ 0.005Amps. All these voltages are labeled at various points on the board. Their is a standard AC jack for input and a standard power connector for the hard disk. This power supply should be very easy to re-use. In my case, I wanted the TO-220 transistors, power resistors, and some of the huge capacitors.

Main Board
The main board is mostly surface mount parts which are easy to remove but the tend to be specialized. I took only some cables from the main board and focused on the power supply board for my scrounging.

Front Panel Boards
DTVRcvrIRReceiver There were two PCBs in the front panel. One was just a bunch of surface mount pushbuttons which I don’t need. The other had an IR receiver module as pictured here. The IR receiver had long though hole legs there were used to solder it down in surface mount fashion. This makes it an ideal scrounge because it has full length legs that work with our solderless breadboards. Also the pins were labeled, what luck. I removed the IR transceiver then cut/broke the PCB to save pin labels, even tacked the part back to the board so that I would have them both when I get to playing with the IR transceiver.

Scrounging the power transistors was a bit harder. These boards often have large heat sinks soldered down to the PCB. You would need a torch to get enough heat to solder the heat sink so I usually try to leave them in place, remove the screws on the transistors and remove them with a soldering iron. You can try a solder sucker or the solder wick but with just three pins I tend to heat all three with my soldering iron while maintaining a pull with long nose pliers. To make it easier I broke the PCB near the transistors and heat sink. This gave me easy access to the parts. As you can see in the picture below.

DTVRcvrPSBroken

There are several tricks you will learn to remove parts once you get into scrounging. There are a few articles here at uCHobby that can give you some starting pointers.

DTVRcvrScroungHaulThe Haul
Here are the parts I kept except for the hard disk which is probably the most important part to keep. Several power transistors, a bridge rectifier, some cables and caps. The screws include nuts and insulators for the TO-220 transistors an the gray pads in the lower right are thermal insulators. A few power resistors and the IR receiver module is there as well.

Comments
What have you scrounged/ recycled for your home electronics workshop?

Posted in Discovering, Parts, Scrounging, Scrounging Parts, Workshop Tips, Workshop Tools.

11 Responses

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  1. Berni said

    I recommend not tearing apart switch mode PSUs like this. Because the working PSU is more valuable than the components on it. The TO-220 transistors and diodes are often not so special parts that can be brought for under a dollar.(about the same for the caps)

    I hate the fact about more modern electronics that they are not so good sources of parts anymore.I like the non SMD boards that had all sorts of desolderable parts on it. But still taking stuff apart is always a lot of fun.

  2. I find I harvest all kinds of cool-looking parts that I’m sure I’ll find some use for, but then never do. Then they sit on a shelf for a year or two before I throw them out. Even though I’ve got a stock of hundreds of different components by now, the one I need for my current project never seems to be among them!

  3. Per @Steve’s comment, what about creating a “great Internet box of old and scrounged stock”? This way we can cycle some of the old scrounged parts collecting dust off our shelves, and replace them with some new parts to collect dust. :)

    @David, I noticed a couple things in the original picture that you didn’t seem to scrounge. Are those RF channel modulators at the front of the mainboard? I also see a PLCC flash. I’m sure the QFPs are probably specialized and not worth it (plus they are a PITA to hand solder), but there seems to be a fair amount of SOIC/SO/SOPs…anything generic and reusable? I also see at least four crystals.

  4. dfowler said

    @Berni… I agree, if it can be used as it, it should be. In this case the supply is well labeled and easily reusable. I just have too many of these from past scrounging. What I did not have was a good supply of power transistors and power resistors.

  5. dfowler said

    @Steve… On of my problems is that I just cant throw away a gadget till I get any parts that might be usable. I have to take a break and gut one of these now and then so I can walk though my workshop.. I agree with Cail, more stuff for a TGIMBOEJ.

  6. dfowler said

    @Cail… Yes there are some other interesting parts but they were surface mount and would be hard to reuse. I did not bother to look them all up to see if any were generic. Maybe I could do a high res scan and put that up for people to look at. If there were some neat parts you would be able to see them that way.

  7. I do the same. I was given a bunch of DVR’s and modems from my work that we are taking parts out of. I was thinking about putting a section on our blog to trade parts. That way if someone is interested in parts we have we can swap.

    I have a nice Sharp LM5H40TA LCD screen, pretty large, that came out of a Rocket eBook reader. Has the 20 pin ribbon on it. I am not sure how to work it just yet. I thought about trading that off if I could for a 4×20 LCD that I can use with ModernDevice’s LCD board.

  8. Berni said

    I would be interested in such a trade if i can get my hands on some useful data on how to interface the screen.Its no problem for me to make a pile of custom code for a MCU to interface it, but i want to see if i can even obtain a document describing the pinouts and interface. Since for some displays out there its nearly impossible to get it.

  9. I have a Emerging Display (http://www.edtc.com/) EW162C1YMY module that I scrounged a while back out of something (a network-centric PC-based computer appliance, IIRC). It looks to be a 2 x 16 block display (each block being 5 x 8 dots), and is soldered to a custom fab board that uses a PIC16LC65B to drive it. I’d be willing to trade all that (LCD, boards, and PIC16LC) for something, or guarantee it would be added to a TGIMBOEJ/scrounge box that headed my way. A partial data sheet (at least the pinout) seems to be here http://www.allelectronics.com/mas_assets/spec/LCD-97.pdf, but an inquiry to company (URL above) might also yield a better datasheet.

  10. Barry said

    Another good item is the tuner module. Depending on the controlling I/O (analog, SPI, etc.), and RF/IF/Output characteristics (freq. range, IF, I/Q outputs, etc.) you can use this for a spectrum analyzer or a front end for a software defined radio. (SDR)

    I’ve build a few “poor man’s” spectrum analyzers and have been working on an SDR using scavenged tuner modules. (from old VCR, satellite receiver and cable converters). The trick is to find the specs on these sometime proprietary parts.

    Old C/Ku band satellite receivers are neat too. You can scavenge a lot of non-surface mount components / parts, particularly ones with a 70 Mhz IF.

    Just a thought…

    Barry (N5NWI)

  11. HI Barry,

    I’m a poor man that has a broken VCR and could use a spectrum analyzer. :) Do you happen to have an URLs that have more details about using a commodity RF tuner as a spectrum analyzer? It sounds like an interesting project, and I’d like to learn more!

    Thanks!