Picture of Projector Bulb Conversion To LED
I received a Projector from a friend December of 2010. It is a Sharp D100U from 1997. It did not have the original bulb, but everything else worked fine. I did some research online to see if I could get a bulb for it and found out that it would cost me $300. I could buy a reasonable projector new for that much. All I really needed was a new light source, so I thought a high-powered LED would work great. 

There were two stages to this project. The first was figuring out how to bypass the bulb checking circuit, and the second was building the new LED light source. 

I found these two Instructables by claudiopolis to be very helpful with this project:


I found the maintenance manual for this projector

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Step 1: Bypassing the Bulb Checking Circuit: Observations and Research

Picture of Bypassing the Bulb Checking Circuit: Observations and Research
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The first thing that I wanted to do before I started taking the projector apart was to see how it currently ran. I plugged it in and turned it on. The fans came on and I could hear the sound of the fans and a faint ticking sound. along with two green lights that indicated Power and Bulb. After about 3 seconds the bulb status light started to blink, and after about 5 minutes the projector shut off and both lights turned red. I shut off the main power switch the red lights turned off. I then repeated that process a second and third time to ensure consistency.

I did some research online to try and find any documentation on the projector. All I was able to find was the user manual. Reading it I found the section that addressed the indicators: Power, Bulb, Temperature. There are three possible states for each indicator: Solid Green, which indicates Normal operation; Blinking Green, which indicates Starting up; and Solid Red, which indicates a problem. 

I removed the top case and accessed the main logic board. My intent was to find the logic signal that was telling the the board that there was a problem with the bulb.

I used my multimeter with the ground connected to a grounding point on the projector and started measuring values of all the wires going to the main logic board. 

I was lucky to find that each set of wires was labeled, but it was only abbreviations. After I recorded all the wires in each state, I made some assumptions as to what each set of wires went to.

RC - Remote control  (Since i did not have a remote for the projector and did not want to buy one I removed this wire and sensor)

BL - High voltage and lamp check circuit ( This is the wire set that I finally figured out was the one I needed to focus on )

LF - Bottom fan cover sensor  ( The two wires on this connector need to be cut and tied together if you want to be able to run the projector with out the fan cover ) 

FF - Fan 

LL - Lamp cover sensor  ( The two wires on this connector need to be cut and tied together if you want to be able to run the projector with out the lamp cover )

Q - Temperature sensor

FN - Fan 

There was also a set of colored wires in one connector that I also recorded, but these ended up not being needed to modify the projector.


dom_i_nick55 minutes ago

Great writeup! I was inspired to try my hand at swapping a 4000 lumen LED into a Dell 2400MP projector. But I'm stuck at bypassing the bulb check. I have this ballast: Do you think I need to short pins 4/5 (type 3 - Front Projection/OSRAM mode)?

Hope to hear back! Thanks :-)

gomme6007 days ago
Hi. Im have ordered a 100w led from ebay but dont understand what driver I need. I have read that it needs constant current but I have always thought that the current must be equal or superior to what is needed. I have bought this:

Will it work ok? Because the current is higher that what is needed and I have read that it can damage the leds? Help please!
CaseyS22 months ago

How did the blacks work out, what was the contrast ratio like - were the blacks actually kind of bright?

I'm looking to make one and I'm trying to figure out how the LCD screen will fare with a brighter light coming through.

ulfilas4 months ago

I've been wondering about replacing the lamp in my DLP projector... Would it be feasible to use a CREE torch? Would something like this work?

use something like this depending on your condition 50 w or 100w

and you may need extra cooling for the led so try this, if needed

Lord AntonH3 months ago

Gotta say, I'm surprised I haven't seen this particular mod pop up more frequently. Cheers for sharing, I'll use this for something similar in a near future.

ánagy109 months ago

Hi! I have just the same problem with my Benq PE8700. Although I found the service manual in no time (, unfortunately I was not able to obtain how to bypass the lamp. Could you give me a hand in this?

Velvelkjell10 months ago
Hi great instructable:)I've got a old HP projector that it's impossible to find new bulb for would you mind helping me with the plans on how to make a rebuild into led or LCD ?bigup:) thanks from Norway
liam231711 months ago

First off, great, detailed instructable! I really like the idea of using an LED for a DIY projector. You seem to be one of the few who have successfully done it. You say that "the main problem is focusing 100 little LEDs, each with its own focal point,
but the combination of the 8000 lumen LED, the reflector, and the lens
works for what I want". Can you expand on this a little bit? Does this mean that you have a slightly blurry image? If you get really close to the projected image can you see the 'screen door effect' (see attached image)? I would really appreciate an answer as this problem is talked about a lot but the effects it has are never really discussed. Thank you!!

invisiblelight386 (author)  liam231711 months ago
What I mean by the 8000 lumen led working for what I needed was that It was bright enough to get enough light through the projector to the screen. With the old 2000lm LED, I tried to converge the light so that I could get as much as possible through the projector. Even with all the modifications it wasn't bright enough. The As far as the "screen door efect"... It's an old projector. You can see the individual squares on the screen but from a normal distance it's not noticeable. I hope this helps. I'm sure that there are far more LEDs that can be usesed for this application on the market now as well.

Thank you so much for the quick reply! I was just having a hard time understanding if the multiple point light source of these big 100W arrays simply caused inefficiency or if they actually made the image blurry. That's why I asked about the screen door effect, it seems like you wouldn't get that effect if the LED caused the image to be blurry. Sounds like it's just a problem of inefficiency though. I plan on using a 100W cheap Chinese LED (they around $30 now, with a driver) on mine too. Again, thank you!

asantos51 year ago
Hello my friend, your project is amazing, congrats!
I have the same problem about the lamp, but i'm in Brazil and my projector is XV-ZW99U from SHARP too, i have the service manual with schematics and wire diagram, but i don't understand how to bypass lamp check :( could you help me?
The service manual is this:

Thanks for your time...
invisiblelight386 (author)  asantos51 year ago

I looked over the document and found a couple spots to check. These are on page 15 and 45. The only way that the lamp check circuit can tell the mother board that it is not working is to have a signal wire from the lamp power to the mother board. The EB connector shown on page 15 might have the wire you are looking for. On page 45 the pin out of the EB wire bundle is shown. Check these wires for the one that sends the signal to tell the MB that the lamp is not working properly. It might be one like EB1 (lamp), EB6 (lock), or EB7 (abnormal). Refer to Step 3 for more details on how to check the wires.

From what i can see you will have to cut the wire a couple inches away from the mother board and connect the end of the wire that is still connected to the mother board to either 5v or down to 0v by connecting it to a 5v source or a ground point.

I hope you can find the right wire. I'm exited to hear how it turns out.


Hello My friend, sorry for the late, but my multitester not working properly and i buy another... then, i test all pins with DC meter, i look up on diagram and see the EB4 (Yellow Wire) is a GND, i use that for all other wires..

This is the voltages:

(I'm confused about colors and pins, then annex a photo of the conector)

Brown + Yellow = 3.28v Before led blink and 0.0v after led blink

Red + Yellow = 0v before and 0v after.

Orange + Yellow = 0.74v before and 0.74v after

Green + Yellow = 1.1v before and 4.48 after (on standy [only main button] 4.48v too)

Blue + Yellow = 2.8v before and 2.8v after

Purple + yellow = 0v before and 0v after.

The photo:

I read step 3 and i think is the brown, but i'm confused if i cut that and splice on the main board side or the ballast unit side or both...

You can help me again?!

Thanks from now!

**PS: sorry for my bad english, is not my country language, and i'm learning yet...

invisiblelight386 (author)  asantos51 year ago

This one is tough. I am curious to see what the middle connector is for (EF?); the one with the red, yellow, and black wires. I do not see it on the diagram. On my projector i found that when i unplugged the BL connector the "ticking" sound that was made every time i started up was gone. This might be the case if the circuit is similar. Maybe try unplugging it and see if you can hear the sound on start up if that's the case. I would not cut any wires until you have a very good idea which one it is.

Very Thanks, my friend, tomorrow i'll try this and come back to tell you what happens.. :D

sk8er61 year ago
Great job breaking down the bulb bypass. Trying to get started on mine today.
roelvdm32 years ago

Nice mod! How did you power the led driver? With the original lamp plug or just on the mains?

kind regards
invisiblelight386 (author)  roelvdm31 year ago
Both LEDs that i bought came with DC drivers. I did not want to mess with the high voltage AC from the projector.
dtommyd2 years ago
I too bought a 20w LED like your first one for a projector I had to give up on. I'm now about to put it in to a different projector. When I bought mine I ordered the 3000k (warm white) version. Seemed like the best idea to match the actual one but I haven't been able to test it out yet. What version did you get? The 3000k or the 5-6000 (White white)? How's your color? It also seems like too much light isn't always good if it's blowing out your whites.
invisiblelight386 (author)  dtommyd1 year ago
I have found that with the LED that i have the picture has a slight yellow tint, but it is not to bad.
redshift1 year ago
"LED Engin's"
Total Internal Reflection (TIR) lenses for die emitters...
Hello, I am new here, and i need some help for my new project replacing the bulb with high power led; i found here some leds at good costs anybody can help me to choose one?
my projector it is a sharp xg p10xe with 3000 lumens
it is ok for it to use a single led with 120 degrees? and if it is, what color temperature should i use, and where should i find a heater? may i use a standard processor heater. i guess that the projector it is cooled enough there in the bulb case! A first question i have, it s worth to do that? Thanks in advance, Bogdan!
Did you use a bright white LED? I've also seen warm white. Wondering if this color temp may be more suitable.
Also the link is down for the bulb assy and lens. I was able to find the pieces to put it together, but i'm curious how the refraction is on the lens. I read some of the comments on the other build link that you referenced. Have you run into the same problems as the other fellow?
invisiblelight386 (author)  joshvonnieda2 years ago
try this one

The reflector and the lens do a good job focusing the LED. Better than the first couple reflectors that I made my self. I'm not sure as to how much of the 8,000 lumens actually gets to the screen, but it is enough to be able to watch a movie and not be dark.

The main problem is focusing 100 little LEDs, each with its own focal point, but the combination of the 8000 lumen LED, the reflector, and the lens works for what I want.
Very cool! You got my vote. I want to try and do this to a projector I've had laying around for years. Hopefully it won't take me quite so long to bypass. :) And thanks for taking the trial and error out of the LED selection. Hopefully I can refer to you for help along the way.
invisiblelight386 (author)  joshvonnieda2 years ago
Glad this could help. The main reason that it took so long was the face that sometimes life gets in the way of my projects, but in the end it was worth it.
Good job! Congratulations. I envy you for that 100W LED.

How did you powered it? Also, mind the heat, check your LED datasheet and see if a temperature probe placed on the LED metal tab confirms you are in the safe temperature area. Otherwise you're wasting that LED lifespan.

How good are the projected colors? Usually LEDs tend to have a bluish light (CRI index) and this changes the color output of the projector. While it might be possible to alter them from the projector's menu, the problem usually remains.

If you can get a DLP type projector to fit your LED in, you'll notice the light loss is much smaller than the 3LCD you're working on there. I gave up on my LED projector bulb for now as I scored a brand new NEC projector (with original bulb) so my hunger for watching movies is satisfied for a while :-)
invisiblelight386 (author)  claudiopolis2 years ago
The LED came with its own power supply. I have been keeping an eye on the heat of this LED. I will be running more tests on it soon. I can always use a larger heat sink as I still have a lot of room inside the bulb housing.

The colors look good. I adjusted some of the values a little bit with in the projector's settings and the white looks very white.

For now I am away at college and do not have the projector with me so the use that it gets is not even close to what I thought it would be. For what I was able to get out of it satisfies me. Free projector plus $100 worth of LEDs and others beats buying a new $500 that I wouldn't have used much any way. Over all it was just a great learning experience for me and has lead me to study electrical engineering.
biolethal2 years ago
Very nice! voted.
*meant to vote, but it doesn't look like it's entered in any contests right now...
invisiblelight386 (author)  biolethal2 years ago
I just submitted it. It is probably still going through review for entries, but thank you.