Before I start I want to say thanks to Woetra(Simon), Riceburner, Monsi, and my coworker Raymond for their help with this project..
I think many people have been waiting to see if it is possible to fix these tail lights rather than paying Lotus $200 a pop every time they go out. So I figured, what the hell...lets give it a try since mine were burnt out anyways.
Well, I have to say, they are 100% fixable. And on top of that, once reassembled, the repair was so clean that you can't tell that it was repaired to begin with. Please note that this is just a temporary fix to get you back to square one so that everything is working like it should. However, since the LEDs are being driven to their limits, they will just burn out again in a few years. I have a few ideas that I'm working with that I'm sure will work to make them last longer...possibly maybe never having to fix them again. I will dive into that once I get it sorted out. But that will come at a later date.
You need the following items to get started.
2 X Soldering iron with fine slant tips (yes TWO)
1 X tube of epoxy glue or something similar(silicon as mentioned by Komiko on this forum is probably a better idea)
1 X small straight blade knife
1 X small tweezer
As many of these LEDs that you need: LS E67B-T2V1-1-1-Z OSRAM Opto Semiconductors | Mouser
Please note that this is a 630nm LED whereas the US lights allegedly should be a 621nm. However, I can not tell any difference at all and it appears finding the correct LED in 621nm is nonexistent. The 630nm should serve you well and there should be no noticeable difference. If you find a LED that matches the OEM spec, please let me know. Even though there is no visible difference, some people may want to use it just for the sake of keeping everything as close to OEM as possible..
1 X donor light assembly to extract the old LEDs
Let me preface by saying, you need to be careful when disassembling the outer lens, inner chrome housing, and handling the LED circuit board. The lens may crack if too much force is applied. This is especially true for lenses that have aged quite a bit.
Step 1: Taking apart the outer red lens.
The outer lens is ultrasonically welded to the base. However, with some effort, I was able to get it off without drama. No heat or any special wizardry was needed. It simple takes a small knife and some patience. First, you need to slowly work the blade in between the red lens and the black base to get started. Slide and ROCK it SLOWLY back and forth until you get the blade to bottom out. See the picture. Once the blade is in, you need to rock it back and forth SLOWLY so that it pries away at the base and the lens. Work a small section at a time until you get all the way around the lens. The red outer lens should come off pretty easily. If done right, it should be a CLEAN break from the base. Watch the video of how I did it.
Step 2: Removing the inner chrome housing.
The inner chrome housing is connected to the base plate at four points. Each of them are at 12 to 6 o'clock and 9 to 3 o'clock. Look at the ribbed underside of the light and you will see that at these points, there is an indicator of where the release is.
You need to take your knife and wedge it from the outside and pry outwards to get it off of the slot. Work in a clock wise fashion until they all pop off. Be VERY careful not to crack the housing.
Step 3: Removing defective LEDs and replace with good ones
The LEDs that were burnt out on mine are labeled LD5, LD6, LD7, and LD8 on the PCB board. These need to be swapped out for good LEDs from a donor light. You need two soldering irons to heat up both sides of the LED at the same time in order to remove it. Watch my video on how to do this.
Here are the four defective LED desoldered from the PCB board. Now you need to do everything from step 1 to step 3 again on the donor lights to extract the good LEDs if you are going that route. If you bought new LEDs then you can get straight to replacing them.
Step 4: Replacing defective LEDs with good ones.
If you bought the LEDs from the provided link, these LEDS have to be modified in order for them to work. The factory LEDs are different than the LEDs linked above in that the anode and cathode layout is different. The form factor however remain the same. The difference is that the factory has one side where both the pins are anode and one side where both the pins are cathode. The new LED have THREE cathodes and ONE anode. One of the cathode pins are on the same side of the anode. So what you have to do is get an exacto knife and bend that extra cathode pin on the anode side and snap it off. You will be soldering it back onto the PCB board with only three pins instead of four. Here is the data sheet for these LEDs if you are interested.
When you modify the LED, make sure you note that there is a small notch on it. This indicates which side the cathode is on. You want to remove the pin that is diagonal to the arrow. Take a look at the this diagram.
Once you got your good LEDs ready for transplant, you simply resolder them back on. Match the orientation that the other good LEDs are facing. Each of the modified LEDs have three prongs that will require VERY precise soldering. If not done correctly, they will not light up. Try not to touch the plastic body of the LED as it will melt quite fast. I would order a bunch of extras just incase. They are quite inexpensive anyways.
Here is a picture of the four good LEDs resoldered back on.
Step 5: Test the light by reattaching to the car.
The prior defective LEDs now light up perfect!
Step 6: Reassemble and epoxy(or use silicon sealant) the lens back to base.
Now we need to epoxy the lens back to the base. Use silicon as suggested by another forum member as it is a better non-permanent solution. It will allow you to serve the lights again in the future. Now you need to reassemble everything. Put the small inner clear lens back into place. Then the chrome housing goes over that. If you are using epoxy, I would just use it at four small points on the lens so that I can remove it later. If you are using silicon sealant you can probably just seal it entirely and it should still be easy to take apart later.
Now, the downside of NOT epoxying the entire ring is water issues. I'm guessing that it is possible that water can get into the housing if the ring is not completely sealed. But then again, that is just a guess. I chose to epoxy it just on four corners for now as I will be fiddling with it more in the future. But do so at your OWN RISK. Use silicon around the entire ring if you want to be safe.
Step 7: Pat yourself on the back!
That's pretty much it! I hope you guys find this useful. Stay tuned for a more permanent fix. I believe that I may have isolated the problem with their lifespan. I have two ideas right now on how to fix it...one hard and one easy...but will need to test them out before I make it public. Cheers!