Archive for the 'Electronics' Category

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Marantz Fixed

After scratching my head over the broken Marantz I finally determined a cause of death.

Some friendly folks at diyaudio.com brought to my attention that the failure I experienced could have been caused if the speaker outputs were crossed, thus overloading the Darrington transistors.

Thinking back to the day it happened I had pulled out the receiver earlier in the day to hook up a Sega Saturn (which only produces stereo sound. eg: no center channel used) after playing that for a while the system was shut off. We returned hours later intending to play Xbox 360 (which is setup for surround sound. eg: center channel is used) and when the system was switched to the surround input by the harmony remote moments after being powered on is when it sparked an popped.

The crossed speaker wire theory fits because a few stray strands could have easily been grounded to the chassis or the other side of the speaker output when I pulled it out for use with the Saturn and then that channel wasn’t used until hours later when it popped.

Also there is no indication of any other component in the unit failing. Having 6 identical amplification circuits I was able to test  the dead circuit agains the working ones and aside from the part that blew everything checked out ok.

After researching parts I found that the transistor that blew is discontinued… replacing it would cost me $10 worth of parts + $8 shipping. that and I was a bit worried that maybe I was missing something and the next time I powered it up it would pop.

I decided to simply reconfigure the amp internally. Since it’s a 6.1 Receiver and I never use the Rear Center channel I basically just re-pinned the amp connector to use the rear center channel amp for the Front Center channel. then I removed a few other key component from the original Front Center Channel to ensure that it wouldn’t receiver power.

After putting it back together and testing it works great… just as it always has.

Since I’ve got a new receiver now I’ll be selling off the old one… I’ve got all of the original accessories, manual, even the original box it came in. I figure considering it’s age and what happened I’d probably let it go for $120 or so.

Marantz SR6200 Marantz SR6200 Marantz SR6200

I’m also going to get rid of the two Component Video/Optical switches I’ve got as well as the HDMI switch I’ve got and I’m thinking about selling off my PS1 and Gamecube as well since I don’t use either anymore.

Crash and Burn… Litterally

So Wednesday night my desktop locked up, which was quite unusual, then it was running slow so I shut it down and it never came back up. It wasn’t until Thursday night that I was able to determine that the Windows Partition of my primary hard drive had crashed. Somehow the formatting had become currupted such that the PC could see the drive but had no idea what was on it, or how things were stored.

My brother had dropped off his PC, which wasn’t working right, so I spent time fixing his (which turned out to be driver incompatability issues… this is the third time this year where I’ve seen windows update upgrade drivers to new versions that don’t work… yay). Once that was squared away I got to work on building another PC from scratch so that I could not only get back online but use it as a tool to help recover (or at least determine the extent of damage to) my crashed hard drive.

I spent most of my day on Saturday working on this… Saturday night however my Marantz SR6200 decided to catch fire… this was turning out to be an expensive weekend. Thankfully shortly after the fire I was able to finish diagnostics on the crahsed hard drive and repaired the borked formatting…

Saturday night this is how my office looked:

My Desk Saturday Night

From left to right: an Xbox I just finished fixing, my post fire SR6200, the PC I threw together, and my desktop with it’s hard drives pulled out the side.

The desktop is running well enough to get my files backedup but in general it’s acting like it’s got brain damage, some programs just flat out wont run, others will run for a while and then just stop working, and it’s a whole lot slower than it was before. I’ve got everything backed up now and a new hard drive on order. In the mean time I’m using the piece-built PC, it’s only a P3 700MHz but it gets the job done.

While finding the source of the fire in the Marantz wasn’t easy, it became pretty clear once I unbolted the amplifier board…

Burnt out Marantz SR6200 Burnt out Marantz SR6200 Burnt out Marantz SR6200 Burnt out Marantz SR6200

It looks like a major transistor failed. The part was an SAP16 NPN 1413 Darlington transistor made by Sanken Electric. I found replacements online for $2 a piece. Hopefully nothing else was damaged and the receiver will be back up and running with a fresh replacement.

Even if I do get it running again I’ll probably just sell it and buy a new Receiver. I’ve been shopping around online and a comparable replacement is in the realm of $1200 new… that’s with similar power and audio quality in addition to new features like support for HDMI 1.3a and HD audio formats.

I’m looking heavily at the Marantz SR6003 or SR7002 to replace this receiver, if anyone has any suggestions let me know.

Saturn to 360 Adapter Revival?

cracksolth left a few comments on the page for my Saturn to 360 adapter, as a result I started looking back into it. I contacted the guys from Acid mods (great guys BTW) to see if they were doing anything different that would help me streamline the design. In terms of communicating with the older “Matrix” style 360 controllers I didn’t really learn much that I hadn’t already discovered; however I did learn that the newer Common Ground style controllers are getting easier to find by the day and that most of the new colored controllers all use that style of innards.

They even supplied me with this handy graphic to determine the difference between a Matrix and a CG controller without having to crack it open.

Difference between Matrix and CG style controllers

As a result I’ve decided to abandon the Matrix style controllers for the time being and just track down a CG style controller to work with since that will allow me to dramatically reduce the pin count.

I’m going to do some playing around and if I like the results I might re-open this project…

My goals this time is to get it to a point of making a “kit” or perhaps even making it easy enough that I can lower the costs involved as well as the ease of install so that more people can get their hands on this. If this is something you’ve been waiting for then you’ve only got cracksolth to thank.

Shoot me an email or post a comment if you have ideas for features you’d like to see.

Door Handle Illumination Circuit

One of the members on Vehicross.info wanted a circuit that would light up the interior door handles of his car for a few seconds after he turned the key off to allow passengers to more easily find the door handles in the dark (they are actually difficult to find in the VX since they’re mounted quite low).

I came up with a circuit using a 555 timer in Monostable mode that looks for the ACC signal to dissappear, since it goes from 12V to float and since the 555 needs a pulse I used both a pull down resistor  to ground as well as an RC circuit to pull the 555 trigger back up.

 Door Handle Illumination Circuit

Power Folding Mirrors

I have a set of power folding mirrors for the 240, I’m thinking about customizing them so that they auto fold in and out with the ignition.

Here’s a circuit I drew up.

Circuit Diagram for Power Folding Mirrors

Fixed Simon

Rudy found an old Simon game from 1986 (the date on the box) that wasn’t working…

 Simon 1986 Simon 1986

 I cracked it open…

 Simon 1986 Simon 1986

…and fixed it up!

Simon 1986 Simon 1986

then I “tested” it for about an hour.

Amp Bypass Harness

To install my new speakers I had to build an Amp Bypass Harness for my 240sx

Amp Bypass Harness for my 240sx Amp Bypass Harness for my 240sx

All Installed

I spent a few hours yesterday installing an setting up my new system. I love doing harness work, all connections are soldered with Silver and then sealed with shrink tubes.

Kenwood Harness for Nissan 240sx with Premium Stereo Kenwood Harness for Nissan 240sx with Premium Stereo

Kenwood DNX5120 in a 1995 Nissan 240SX SE Kenwood DNX5120 in a 1995 Nissan 240SX SE

This unit is AWESOME and everything I wanted it to be. The navigation works fantastic, the picture quality is great and it sounds fantastic. All of the touch screen controls are easy to see and understand too.

I still have some stuff to finish up though, I need to find a more pertinent route for the GPS receiver module as right now it’s just running along the floor under the passenger’s floor mat. I need to get an antenna adapter so I use the regular radio, and I’ll probably want to bypass the factory amp in the trunk as right now it’s way too loud, and the sound quality will probably be better coming directly from this unit.

Saturn to 360 Controller Adapter

May 1st I decided I wanted to tackle a big project. I wanted to do something that no one had attempted before and was beyond my current skill set. I had seen numerous inquiries on the forums from people who wanted to know how hard it was to use “X” controller with the Xbox 360. It always boggles my mind how little people know about this stuff and how 90% of the time they simply assume they can just cut the connector off of any cable, twist some wires together and call it a day. I wanted to do something to show everyone that these things were not impossible, nor were they that simple. I eventually decided to build an adapter that would allow me to use a Sega Saturn controller on the Xbox 360.

Saturn to 360 Adapter Logo

I chose the Saturn controller because the data protocol seemed simple and straight forward but complex enough that the circuit design would be interesting and challenging. I assumed that the converted output from the circuit would work easily with the Xbox 360 controller without any major problems, that turned out to not be the case.

I started off under the assumption that since the data from the Saturn controller was a simply multiplexed across four channels I could use some demultiplexers and get some good results. I didn’t know much about multiplexers/demultiplexer and as it turns out they don’t work the way I thought they did. So this didn’t work out.

Saturn Controller Protocol and PinoutSaturn Adapter First Test using demultiplexers

After the false start with the multiplexer I went back to the drawing board and started researching microcontrollers. I had limited experience with microcontrollers in the past but I knew enough that I knew it would work and that I would be able to figure out how to make it work. I eventually decided to go with a Microchip PIC solution using the PICkit2 and its included microcontroller. The first test was successful.

Saturn Adapter First Test with Microcontroller

After that I did a simple test to interface the microcontroller output to the Xbox 360 controller using transistors. This test was also a success. I had to actually use the guts of an Xbox 360 controller for communication between the console and the Saturn controller due to Microsoft’s security system. All major peripherals, especially the wireless ones have their communications encrypted and require a special chip sold only from Microsoft. This is also the reason no 3rd party wireless controllers have become available yet.

Once I scaled the transistor solution across all of the buttons I soon learned that the transistors would not work as anticipated. while my prior test had seemed to work, it had some side effects that were not immediately apparent.

Saturn to 360 adapter 1st Prototype with transistors

I rebuild the whole section of the circuit between the controller and the microcontroller and I ran a ribbon cable from the controller to the bread board just for my own piece of mind. This actually worked great but I was having the occasional voltage problems since the circuit was so large and drawing so much power. The power issues were worked out by simply adding more batteries.

Ribbon Cable Controller InterfaceSaturn to 360 Adapter Prototype 2a using Analog Switches

This ended up being the final version of the adapter. There were a few loose ends that I never tied up but I had met the goals that I had set out to achieve. I showed that controller adapters were possible albeit not easy either.

To my Surprise this project caught the attention of A LOT of gaming news organizations. The one I am most proud of however is an interview I had with Official Xbox Magazine in the UK. I got two whole pages dedicated to the interview and pictures as well as a teaser blurb on the front cover and main index. It has since been reposed on CVG sans pictures.

Here is a link list of all the other websites that covered it:

If you know of other news sites or corners of the web that ran an article or had some comments on it, let me know.

If you’re interested in the more technical side of the project the project log can be found on the Xbox-Scene forums. There is also a wrap-up post with all the important bits in one place. Another interesting bit is a fellow by the name of SaturnAR posted with some in-depth information on the Saturn analog controller which is well worth reading and he remains the only source of this info that I’ve ever seen.

Custom Easy Button

I’m sure nearly everyone is familiar with the Staple’s Easy Button from the commercials. Many of you are probably also aware that Staples actually sells Easy Buttons for $5 at their stores. It’s a simple device with batteries a speaker and of course a big button. Upon pushing the button you hear the “That was Easy…” catch phrase.

The Easy Button

I bought one to use at work since “easy” has come to be known as the ‘E’ word since certain people have come accustom to using the term to describe the difficulty of things that are decidedly NOT easy, at least that’s the reality that is usually discovered after far too little time has been dedicated to a particular project or task. Hence the button gets a push whenever anyone uses the term, or when something is completed successfully that actually did end up being easy.

While it’s entertaining, the gag can get old. For a brief period of time I was moved into the engineering area which sees a lot more traffic and my Easy Button saw it’s fair share of pushes as people found it funny to press as they walked on by chuckling to themselves as if they had just perfectly executed a joke. It didn’t bother me but it was clear that a few others who sat near by were weary of hearing “That was easy” continuously throughout the day… I decided that, for the benefit of myself and those who sat within ear shot, I needed to get some revenge.

I decided that since the Easy button was really just a button attached to some circuits I could very easily just make it a button attached to some different circuits; more specifically a circuit that could play custom messages instead of a pre-recorded one.

I went to radio shack because I remember them selling little voice recorder circuits in the past. I didn’t find one of those but I did find a key fob device that featured a voice memo function among other things. I decided it was small enough that I could strip off all the other crap that I didn’t need and shrink it even further if need be.

[I regret not taking any pictures of the key fob device pre-hack]

I started by pulling apart the Easy Button to see if it had the necessary space I would need to make it work. As it turns out there is a large piece of metal inside the button used to prove it with the satisfying CLICK when pushed. Also inside were two pieces of metal rod to give the button weight. I decided to do what i could to keep these features intact so that the button would not loose it’s quality. Thankfully the area under the metal plate was empty space albeit tight when taking into account that the plate needed to flex when the button was depressed. I also decided to keep the speaker since it was much larger than the one included with the key fob recorder.

Once I pulled the key fob device apart probed for the appropriate points I needed for microphone, speaker output, play and record buttons, as well as the points for the batteries. I pulled off all of the unnecessary stuff and got the circuit down to a really small size. Before attempting to fit everything into the Easy Button case I first made sure that the circuit worked.

Easy Button Circuit Test

Once I ensured that the circuit worked the way I intended I mounted the voice recorder circuit into the empty space below the metal “click” plate and ran wires. Since the metal plate would likely rub against the circuit I put some electrical tape over it to provide isolation from shorts.

Easy Button Voice Recorder Install Easy Button Voice Recorder Covered

Next I put the metal plate back in place and screwed down the original Easy Button circuit which was modified to short out all of it’s components except for the actual button, which was now connected to the voice recorder.

Easy Button Modified Circuit

Since I was using a different circuit that was designed to run on different batteries at a different voltage I decided it would be best to make the Easy Button fit the circular batteries as opposed to building additional circuitry to adapt AAAs. Also the battery holder portion of the button provided ample room to mount my microphone and record button as well. I started by modify half of the battery compartment to fit the circular batteries by bending and cutting some of the original battery hardware.

Easy Button Modified Battery Door

I then modified the other half of the battery door to fit the microphone and record button, both of which I got from my spare parts box. I then put it all back together and had an easy button that looked and felt just like the original but now could be programmed to say whatever I wanted.

Easy Button Record Button, Mic, and New Battery holder Easy Button hacked and ready

To get back at my co-workers I recorded the phrase “Ha Ha! Not this time. Get back to work.” and proceeded to get a good chuckle at every unsuspecting person who walked by pushed the button and then turned around for a double take when they realized that the button was heckling them rather than responding with the soothing Staples advertisement.