So I decided to try my first mod on a Small Sun ZY T-08 using a .22ohm resistor as shown here(post #45) by viffer750. Ordered the .22ohm resistor, obviously the wrong wattage, mine are 2 watt, viffer’s are probably .5 watt, just guessing. I completely burned off one of the original 3 parallel resistors, first time it didn’t work so I did it again, success the second try, not sure of the amps buy it’s brighter and get’s hot a lot quicker. It’s just real ugly. 
Ugly or not it works!
Congratz on a successful first mod. :party:
I would at the minimum put a dab of Goop between the resistor and board, vibration will eventually kill the joint. The glue will prevent vibration from working the resistor back and forth til the joint failed.
If those are only current limiting resistors on the power path, I will tell you what I do, short them out, remove them and put a piece of copper there instead. If your emitter/battery can handle it. With such a badass mosfet I would not really worry about burning it.
Done this with switching drivers and it works too and those have more components on the power trace. Still cope just fine.
Any resistances below 1 ohm, are pointless, you will give it more by the thread contacts, battery contacts, etc.
Contrats southland. Looks better than first attempts. Hard to tell from the picture, but it looks like you may have shorted the resister bank with the solder blob/resister wire on the far right resister pad. So you may be a max current.
If they are shorted you could be getting 5A (at the tail) with fresh batteries, to much for the health of an led on Aluminium.
Two choices, either get rid of the short or even better get the led on copper :bigsmile:
Now you have done your first mod, I’ll bet you can’t stop.
Cheers David
I probably did short the resistors, it gets hot pretty quick. What is the correct wattage for the resistor I should be using? Where do you guys buy the resistors, bought these off Ebay.
I got mine from FastTech link to resistors but are available just about anywhere.
These are very small R220 resistors, so you will need a decent soldering iron and some practice on things that small you need magnifying glasses to see properly :nerd_face: you get 100 so plenty to practice on, one hint is to use solder paste.
You could get other values as well but using 2 parallel gives you r110 and two in series gives you r440, sense resistors do not take the full led current so the tiny ones are enough.
Cheers David
I like Pommie's idea of keeping the driver the way you have it and just putting the emitter on a copper sinkpad or notigon. Better yet, buy an XM-L2 U2 1A already on a Notigon and dedome it with gasoline.
Sounds like the link you provided shows how to get to 3.2 amps using a .22 ohm resister. If you want something different, We need more info to answer your resister size question. What current do you want to go to the emitter?
And, one of these questions:
- What was the original current to the emitter and what were the 3 resistors labeled?
- What was the original current to the emitter and is the voltage drop you measure accross one of the resistors with a DMM when the light is on high?
That will get you a theoretical number, but actual current may end up being different due to a lot of different factors. Ideally, you should use a DMM to measure actual current and then adjust resistors to get to your target.
Well it works, that definitely is better than I did my first time. Keep it up southland, your probably hooked now.
This my source for cheap electronic parts, they have a warehouse in the states somewhere. Sometimes I have got orders in as little as 4 days. Sometimes it takes a week or two. Depending on where it ships from I guess.
You can get a thousand or more components for 20 or 30 bucks. Shore beats radioshack. :bigsmile:
http://www.taydaelectronics.com/resistors/1-2w-carbon-film-resistors.html
I read the rest of the T08 thread you linked above. Looks like stock current was 2.3 - 2.4 amps. I can't make out the resister labels though. There are a couple folks that when more aggressive on the resistor mod and had issues later on.
0805 resistors can only handle about 1/8th watt. Here is a 1206 (1/4 watt) resistor that should enable you to do most resistor mods.
If I shorted out the driver would the modes still work because the modes still work. Are the resisters the only thing I need for most modding or would I need other things, what are the most common sizes I would need. Have the Hobby King solder station.
If I'm looking at photo correctly, you only shorted the voltage sense resister bank. So basically you have set the driver to max output. I don't know about this driver, but most seem to handle it well. You should still have all your modes.
As Pommie discussed above, you can combine the .2ohm resistors in series and parallel to achieve other levels of resistance. You only need a soldering iron and solder (rosin-core for electronics).
You can pick up a few sizes of sense resistors at fasttech and wait awhile. Or pick a few from digikey and have them in a few days. You know which one is going to cost you more. R500, R200, R100 and R05 and maybe R01. 0805 Probably more common but sometimes 1206 is used. You could stack (parallel) 2 R200 to give you a R100 and the same with 2 R100’s to give you a R05 but its a lot easier to just solder one resistor. You don’t necessarily need all the sizes I listed.
Went ahead and did a dedome on this light, now the modes don’t work, didn’t touch the driver. Did the dedome by placing the whole pill in about 1/2 inch of has with the driver still attached but not in the gas. Used a very small bottle to keep the pill upright. After the dedome I washed the whole pill good with water for a couple of minutes. Could the water have messed up the driver? Maybe it just needs to dry out more.
HOLY SNIKEYS!!!
They are surface mount resistors...that thing looks like you tried to weld a 55 gallon drum on the hood of a car.
Yeah he used a 1/4 watt resistor
But hey, if it's stupid but works...it ain't stupid
Don't worry you will get better with practice, and a fine tip solder point on your soldering iron
Here is a link to a whole bunch of SMD resistors and whatnot...(in case you were ever looking)
http://www.fasttech.com/search?SMD
you’re not the only one 
One or two of the people in the thread you linked to spoke of mode issues a while after doing aggressive resistor bank mods. The resistance mods may or may not have been the cause. Poor driver seating and other things can cause mode switching issues too.
For sure, water could be causing the problem. It can be under a chip causing shorts between pins and such. I've been in this situation a couple times, but lucked out by totally drying the parts. I've had some luck with using heat to evaporate the moisture, but it doesn't seem to work every time. What has worked for me each time has been sealing the part in a zip-lock bag with a desiccant pack for a few days. If you don't have a desiccant pack, rice is supposed to work.
Best wishes for good luck.