Hey everyone. I am new to the modding end of things and figured I would use this as a place to start. Ever since receiving my ultrafire wf-502b ssc-P7 almost a year ago, I have been severely disappointed in its performance.
After putting the drop-in in a drawer and finding much more satisfaction in my xpg drop-ins, I decided to pull it out and measure at the tailcap. Sure enough its only pulling .6A.
Long story short, I decided to order this driver to replace it with.
Should work with that driver, it is a 2.8A device so it'll give the LED the current it needs. I know old4570 likes P7's so hopefully he'll chime in. If not, a PM in his direction will probably give you useful info. I've not used this driver so I don't know much about it.
In general, warm up the contacts on the LED with a soldering iron and pull off the wires to it. If the wires are the same colour, mark one of them so you can tell which is positive and which is negative.
Remove the LED from the pill so you won't overheat it.
Unsolder the centre spring from the old driver and keep it, you may need it though the new driver appears to have a centre spring.
Remove the blobs of solder that bridge the edges of the driver to the brass P60 pill.
Pry out the old driver. Unsolder the wires from the old driver - they are already the right length and rating. Again make sure that one of the wires is marked if they are the same colour. If they are red and black this is not an issue.
Attach the wires to the correct points on the new driver. Black wire to negative, red wire to positive. From looking at the rather poor pictures on the KD site, I'm not sure where the soldering points are. With any luck the board will be marked LED+ and LED-
Push the wires through the appropriate holes in the pill.
Put a couple of good blobs of solder to bridge from the outer ring of the driver to the brass body of the pill.
Solder the wires back onto the LED. Pay attention to polarity, they will only work one way round.
I do it differently but not much. I do not remove the led.
I disassemble the light and take out the dropin. Put the dropin upside down so the reflector side is sitting on desk and you see the spring from the dropin. Heat the soldering iron, and gently remove as much solder from the stock driver that is contacting the pill assembly. Use some copper wire (multi-string) without insulation to aid the removal of solder. Do not overheat the driver, be fast and neat. After the excess solder is gone use a flat head mini screwdriver to pry out the driver but carefully. Desolder the red and black wires from it. Solder the new driver on the exposed wires and put the circuit board back into the pill. Solder the outer ring in a way that makes contact with the (usually brass) pill. Again don't heat more than really necessary. Be quick (i need 2-4 seconds for making 1 edge contact at a time). If you heat up anything greatly wait half a minute to heat it again if need to do more work on it. Practice makes perfect. Then solder the spring if not present already and reassemble the light.
Use some alu foil around the dropin for a snug fit.
I strongly suggest you to get a decent solder from a local electronic shop not from DX. It is like night and day difference.
Another method I find easy and avoids removing the emitter is to simply use a razor knife to trim away the solder connecting the driver to the pill (after disconnecting the leads from the emitter). It cuts like butter and there's no worry of overheating the board.
You will probably need to file the edges of the new driver down a little. It's not a bad idea to file it pretty flat on one side so that you can pry it out again if necessary. I wouldn't typically take the emitter off either unless they didn't do a good job of it originally.
Home Depot has 25W Weller soldering irons pretty cheap ($12 I think). There are a couple of different versions and one includes a regular soldering tip and a needle nose one that I wish I had for soldering stuff on these little driver boards, so see if you can find that one. You don't want too much wattage for little electronics, so don't think 50W is a better deal.
That's a good driver for the P7. You'll be blown away by how much brighter it is.
