Author Topic: SMD Resistor Help... Missing one LED on my RS96 Red Scarf III!  (Read 1605 times)

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Offline onmybikedrunk

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So yeah...


I'm super bad with electrical diagnosis issues...


This is my dilemma:
I ordered a RS96 from Taobao (no agent - adventurous!) and I took every precaution necessary during the build but somehow I missed the fact that one of the SMD resistors (happens to be for the ESC key) was botched during production.  I of course noticed this after the switches/SIP sockets were all soldered in and I was in the final testing phase... I am going to attempt to repair myself but the said resistor isn't carried anymore by the major retailers (digikey/mouser).  It isn't even listed on the manufactures website (Susumu).


The SMD Resistor in question was marked "271" which can be seen here on Digi-Key.  It seems they are no longer in production and I can't find them anywhere in the U.S.  The closest match I can find is the following:


- 271 Susumu on Mouser: only difference compared to the stock resistor (DOA) is this one has a Power (Watts) of 125mW, 1/8W vs. the stock which has .25W, 1/4W.  In fact Digi-Key lists this as a comparable replacement - even though they don't have them in stock.  Is 1/8W going to make any difference if EVERYTHING else down to the package size is all the same?


There are other options with slight variations but I'm very unsure of what specs matter the most and what don't really matter at all for this particular application. 


Any help would be greatly appreciated!

Offline suicidal_orange

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Re: SMD Resistor Help... Missing one LED on my RS96 Red Scarf III!
« Reply #1 on: Wed, 23 March 2016, 06:10:27 »
The wattage rating is the maximum amount of power that can go through the component without it breaking, so using a 1/4W instead of a 1/8W is like using a pint glass to carry half a pint - it will do the job just fine, but has unused potential to handle more.  The 271 is the important part, meaning 270 ohms :)
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Offline flabbergast

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Re: SMD Resistor Help... Missing one LED on my RS96 Red Scarf III!
« Reply #2 on: Wed, 23 March 2016, 06:51:30 »
You can actually use pretty much any 270 Ohm resistor of the correct size (0805). I'm pretty sure they'll have some of those in stock at every major supplier.
With 270 Ohms the resistor will see at most 0.06W of power through it, so you'll be fine with the standard 1/8W resistors.

Offline onmybikedrunk

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Re: SMD Resistor Help... Missing one LED on my RS96 Red Scarf III!
« Reply #3 on: Wed, 23 March 2016, 10:53:26 »
The wattage rating is the maximum amount of power that can go through the component without it breaking, so using a 1/4W instead of a 1/8W is like using a pint glass to carry half a pint - it will do the job just fine, but has unused potential to handle more.  The 271 is the important part, meaning 270 ohms :)
You can actually use pretty much any 270 Ohm resistor of the correct size (0805). I'm pretty sure they'll have some of those in stock at every major supplier.
With 270 Ohms the resistor will see at most 0.06W of power through it, so you'll be fine with the standard 1/8W resistors.
 
Ok thanks!  I figured as much, but like I said my brain goes "derp!" when it comes to this stuff.  I'll order the one linked.  Thank you both!