Dynatel 956DSP Repair and Mod


Once inside it was apparent that this thing was made to withstand some abuse. Here a few pictures of the unit;

My dynatel

Here is a picture of what the test leeds look like. the cylindrical part on the aligator clips holds a bed of nails to make connections. Just squeeze a wire and you are making connections.

This is where the pin header was removed from the PCB and I simply soldered leads from here to the barrel jack. Nothing fancy really. This setup has served me quite well, until something awful happened about 6 months ago.

This is the finished adapter. It is just a standard 5 mm barrel jack, and some beefy washers to fill the gaping hole. I recently wrote what kind of adapter would be acceptable directly on the case to avoid mishaps.

Now for some pictures of the inside, and the latest repair.

Somewhere along the way someone decided to charge the Dynatel 965 DSP, I’m not sure with what or how, but they made it not want to turn on again. I couldn’t be bothered with it for the last six months, until I saw it on top of ome junk in my shed. So I brought it inside and got to work taking it apart.

The construction of this unit is very rugged. As I mentioned earlier it had been run over by some sort of vehicle, the tire marks looked as though a large truck had drove over the bottom end of it. The only damage that was apperant was the plug connector of one of the leads was broke and one corner has a small crack.


All of the screws have threaded inserts and are stainless steel. There are also gaskets and o rings on everything you can imagine. I ‘m not sure what sort of standard this unit achieves but I imagine it is at least a little waterproof :). It is strange however that there are no markings on the unit as to its CAT rating or ANYTHING. There is just some information about its last calibration and who to contact if you need such calibration.


The small board on top contains the voltage input, charging and distribution.

This is the other side of the first big PCB seen in the image above. It has the connections for the 5 test leads and has a ton of analog circuitry.

And lets not forget 10 relays! I have not even begun to figure out the signal path inside of this thing as there is just so much, and everything interconnects with headers etc. Not to mention some parts being on the back of a PCB but on the front of another, it gets confusing trynig to trace anything.You can also see the 5 input conections along the bottom. They are like a miniature banana plug i suppose.

Here are a few pictures the rest of the analog boards followed by the LCD controllers at the end.

And finally the back of the LCD. It is quite a nice unit, as it is a dot matix type with a back light.

This unit also uses a “Dragon Ball” processor. followed by a few pictures of some of the support devices. These are also found in older palm devices. that could make for a more interesting story I think. Linux would therefor be a possibility. Well beyond my abilities though I’m afraid.



Ok, so here is what was damaged.

The orange arrow points to a damaged diode, the red circle was a SMD fuse, which I replaced with some solder (not like it did it’s job anyways), and the orange circle is an inductor. the next picture shows what happened to that inductor. Also not the brown marks on the silk screening around L9.

This image was taken with my video microscope at 200X magnification. Left is the replacement, right is the…well gun shot victim?! This inductor does how ever work as a 4.7 nf capacitor now. Go figure. there was also no way for me to tell what the value was supposed to be so I just randomly grabbed one and soldered it in there. This was probably the crappiest repair I have ever made, but I really didn’t care that much and the value does not seem important in this case.

And finally it works again! One neat thing abou this meter is that you can change between wire pairs to make measurements. See in the image below how the box with the arrows comming form the red and black marks on the side( means red and black leads) is in bold, this means that that pair is selected. you can then toggle between red/green, black/green, and red/black again.



This is probably a bit borring for most of you, I just thought some of you would like to see all of those innards. I took a look around the interwebs for a similar one, and found that they sell for $1500 on Ebay. They look a whole lot nicer than this one though.

If there is someone out there who would want this unit to play with let me know. You can have it for the cost of the shipping, I just really have no use for it anymore and I think someone else could enjoy it. It weighs roughly 1.5 pounds with the test leads and I live in Ontario Canada. Just send me an e-mail at jordan@electronicsjunk (dot) com, or leave a comment here.



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2 responses to “Dynatel 956DSP Repair and Mod”

  1. EschatologicalEngineer

    15th Oct, 12

    Great Teardown! This is the first time I’ve visited your site. I appreciate the detailed images and especially find the close up of the problematic diode helpful. I’m slowly teaching myself repair as I dive deep into electrical engineering/reverse engineering. I just wanted to share my appreciation for your site and this post. I love this stuff!

    Covered in flux,

  2. jordan

    24th Oct, 12

    Thanks! It is great to hear from readers. I love how the world is now moving towards fixing stuff especially considering how much stuff gets dossed in the trash these days.

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