You cannot get LED only. You will have to replace the complete front screen including the glass, digitizer, and LED. I found out why the LED doesn't work after trying glass replacement. It is the pressure caused when lifting the glass that causes LED not to work. I don't use a spudger anymore to lift the glass. It's best to use molybdenum wire.
I replace two or three broken glasses of iPhone 5 daily. I know it is ugly and tough to do it, but is manageable. Removing glass is not hard, it is removing glue! I know I don't have to do this when the part price comes down as low as iPhone 4, 4S. Until then I will just have to remove the glass due to popular demand.
The wire is called molybdenum that is used cut between the glass and digitizer. It is VERY difficult use that wire because of the glass is already hot. Also it is silicon that lies between glass and digitizer and I have the replacement silicon but it's almost impossible to put that back on the replacement glass clean. It has to done at zero dust industrial level, not recommenced for DIY at all. Just wait for the whole front assembly price to come down.
I used the source provided by first post to buy some HTC EVO 4g mic before, kinda slow shipping but it came and I used it. Now I need to order again, went back their site, but it's now all changed and they are charging $15 for 3 mics (less than 1oz total). Plus they changed their website and company name and I don't even know if I was right place or not. I need to find another source for this part.
replacing 4R7 is not an easy job. It's not a job with soldering iron and removing chit out and in. I repair iphones professionally and I even get nervous when I have to remove such and 6R8 on 3Gs. If you want to get an experience with a chance of sacrificing your board, try it, otherwise look for a professional.
I would like to know if Alex's advise solve the problem or not. I have same issue, have iPhone 3G with no picture problem. No backlight or anything. I even tried with new screen but won't display anything. The phone is on as it gets deteced by iTunes and vibrates when switched to mute. I made sure with connector and tried home and power button deal, but still nothing.