# Repairing an Aristo Craft Revolution Receiver



## dbodnar (Jan 2, 2008)

I recently damaged one of my Revolution receivers. I am sure that Aristo Craft would have repaired it for me but I tend to like to do such things myself if I can.

I just posted details on the repair that also includes information on the inner workings of the Revolution receiver. 

Have a look:

Revolution Receiver Repair Notes 

Please let me know if you have any questions.

dave


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## Torby (Jan 2, 2008)

Cool. 

I've only started to fiddle with surface mount parts. I love your web site. Perhaps you need to post this over at teh Aristo forum.


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## aceinspp (Jan 2, 2008)

Dave good info. Guess its ok for folks to do these type of repairs on AC electronic board . I got blasted on the AC site for doing a repair on a an elite power pack that I replaced the fan in. AC says these type's repairs should be left to Them. Guess times have changed. Later RJD


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## Greg Elmassian (Jan 3, 2008)

I remember that, you replaced a 12v fan for a couple of bucks, and Lewis did not like you opening your power supply and admonished you on the forum. 

He wanted you to ship it back and pay the postage which is of course was more than the fan. 

Times must have indeed changed if the warranty is not voided. 

Thanks for blazing the trail Dave! 

Regards, Greg


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## Del Tapparo (Jan 4, 2008)

That is some nasty solder assembly in that photo of the 8 MOSFETS. I hope that was your rework and not the quality coming from A/C.


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## Greg Elmassian (Jan 3, 2008)

(I held my tongue on that one Del)... 

Actually looks like a couple of pins bridged in the right foreground. 

Regards, Greg


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## dbodnar (Jan 2, 2008)

Posted By Greg Elmassian on 15 Oct 2009 10:04 AM 
(I held my tongue on that one Del)... 

Actually looks like a couple of pins bridged in the right foreground. 

Regards, Greg 
Greg - no need to hold tongues.... if you read through the notes on the web page I mentionted that it does not matter if the pins are bridged on the source and drain leads as they are connected together on the board. I also noted the chips that I replaced and those are the ones that were obviously done by human hands, not by machine. The chips were very nicely placed before I removed them!

dave


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## Greg Elmassian (Jan 3, 2008)

Sorry Dave, I did not read closely enough to remember the pins could be bridged. 

And I held my comments in deference to you. 

Now that is cleared up, what kind of foam is that between the heat sink and the fets? looks kind of soft, but I'm not familiar with foam used for thermal transfer, maybe it's higher density than it looks. 

Regards, Greg


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## dbodnar (Jan 2, 2008)

Posted By Greg Elmassian on 15 Oct 2009 10:30 AM 
Sorry Dave, I did not read closely enough to remember the pins could be bridged. 

And I held my comments in deference to you. 

Now that is cleared up, what kind of foam is that between the heat sink and the fets? looks kind of soft, but I'm not familiar with foam used for thermal transfer, maybe it's higher density than it looks. 

Regards, Greg 
Greg - the heat sink material is new to me, too - it appears to be rubber and fairly thick, about 2mm - I have found rubber heat sink material at Digikey and Mouser but nothing anywhere near that thick. Their offereings are for pads to place between a power transistor and its heat sink, not to envelop the IC as this does - whatever it is I like it! I would love to find a source for it.


dave


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## Greg Elmassian (Jan 3, 2008)

Be really nice to know the thermal characteristics, since most foam is "spongy" because of air (poor conductor of heat) in it. 

Most of the thermal stuff I have found has a metal mesh or metallic particles in it, but of course, could not handle the differences in the tops of the fets on this board. 

Maybe it is special stuff, would think so... I googled a bit, dow makes some stuff with silicon, but not a foam tape, their "tape" is metal filled and only a few thousandths thick, like the stuff used between a microprocessor and the heatsink.

Regards, Greg


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## aceinspp (Jan 2, 2008)

Ha made in China. Later RJD


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## George Schreyer (Jan 16, 2009)

It's a thermally conductive elastomer. The conductivity is typically not that great in this material, but it is actually more reliable than thermal grease which relies on absolutely parallel package placement, not an easy task. Aristo might be using a material that is better than the stuff that I evaluated several years ago. 

The best thermal path for that kind of package is out the leads and onto the wide traces on the PWB. The elastomer probably picks up more heat from the margins where it presses against the PWB than against the packages themselves. The encapsulant used for that kind of package has some thermal conductivity, but not a lot.


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## Greg Elmassian (Jan 3, 2008)

What is your guess George? Silicon based, or carbon impregnated? Those seem (to me) to be the best candidates? 

Will take mine apart this weekend to have a look. 

Regards, Greg


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## George Schreyer (Jan 16, 2009)

the stuff I evaluated was a partially conductive silicone based and metal impregnated material. I doubt that Aristo is using the same stuff as they press it over the leads of the device.


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## George Schreyer (Jan 16, 2009)

this is from Wikipedia on elastomers 

Non-dyed silicone rubber tape with an iron-oxide additive (making the tape a red-orange colour) is used extensively in aviation and aerospace wiring applications as a splice or wrapping tape due to its non-flammable nature. The iron-oxide additive adds high thermal conductivity but does not change the high electrical insulation property of the silicone rubber. This type of tape self-fuses or amalgamates without any added adhesive.


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## dbodnar (Jan 2, 2008)

Gentlemen - I found a manufacturer of a rubber heat conductive pad like the one we discussed earlier and ordered some samples. They came in this week and I did some tests. 

I have photos, test results and some observations on my web page at:

Rubber Heat Sink Material Information

The good news is that the material I received worked as well as the original material on the simple test that I performed. 



dave


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