Introduction: Projector Bulb Conversion to LED

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

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

Picture of Bypassing the Bulb Checking Circuit: Observations and Research

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.


Step 2: Bypassing the Bulb Checking Circuit: More Research and Tests

Picture of Bypassing the Bulb Checking Circuit: More Research and Tests

With no luck on the logic board I turned my sights to the main power supply. I did some more research and found that some projectors use optocouplers which are used to measure the feed back from the bulb (see the photo for a full illustration of how one works). I gathered from my research that I had to bridge the optocoupler that controlled that bulb to trick into thinking that it was working fine. 

I started to dissemble the projector even more; all the way down to the power supply. I found the three ICs that I thought were the optocouplers and through trial, error, and almost bricking the whole projector I was right back where I started. 

The projector sat in pieces on a shelf for a couple of months while I was busy with school and other things. 

I came back to it in the summer and tried again. I reassembled it and tried to figure it out with more research and more trial and error. I was able to get the high voltage arc to stop by unplugging the BL cable from the main board, so I was starting go get some where.

Step 3: Bypassing the Bulb Checking Circuit: Found the Circuit

Picture of Bypassing the Bulb Checking Circuit: Found the Circuit

Once again, the projector sat on a shelf until December. It had been almost a year since I received the projector and I had barely gotten anywhere. I was starting to think that it would never work. Just when I was about to tear it apart and use it for parts, I decided to give it one last try.

I focused on the main logic board. I figured that if there was any signal coming from the power supply it had to connect to the main board to tell it to make the led blink and shut off the projector. 

It was then that I realized that maybe for that 3 seconds when the indicator was solid green that it was sending the right signal that was telling that the projector was working fine, and the moment that it started blinking the signal would flip. I had not tested that in my initial testing of the main board, so I gave it a try. 

I was looking for a wire that was 5 volts or 0 volts with the light solid green, and 0 volts or 5 volts when the bulb indicator started blinking.

I focused on the set of three wires that were coming from the power supply to the connector labeled BL. This cable was the one that I had unplugged to get the high voltage to stop, so I checked it for the values that I was looking for. 

Just as I had thought, the middle red wire started at 0 volts and jumped to 5 volts when the indicator started blinking. I cut the wires and spliced them together to bridge the connector. Then I put the projector back together to test it. I also found that the orange wire was the one sending the signal for the high voltage start up. I cut that wire so that it was no longer connected to the main board.

I turned on the main power switch and then pressed the power button. The fans came on and the green indicator lights came on and stayed on. I thought that time had stopped. I stared at that little green light for almost 30 seconds just to be sure that it was not blinking. 

I had finally found and fixed the circuit that had taken me almost a year to find. 


Step 4: Building the New LED Light Source: LED V1.0

Picture of Building the New LED Light Source: LED V1.0

The next step was to find an LED that would work. The original bulb was a 265 watt metal halide, 2000 lumen bulb. I did some more research and found a 20 watt, 2000 lumen LED for $20 and the 18 volt power supply for $7 from 

If you have ever ordered from DealExtream then you already know that it takes about 3 to 4 weeks to get what ever you ordered. I waited all month for the LED and driver to arrive. 

I first did a quick test to see if the LED actually worked, and it did.

Next I had to build a housing for the new LED to mount to. I used a piece of PCB board as the main piece and cut it to fit inside where the original bulb housing would go. I attached the LED chip to the heat sink and used heat sink compound to ensure a good heat transfer. I connected the heat sink to the PCB using some aluminum brackets that I made. I soldered the LED to the power supply and used heat shrink tubing around the wires to keep the heat from the LED from melting it. 

I put the new LED housing into the projector, set it up, and tested it out. The picture was not very bright, and I had to have all the lights off just to see it. I adjusted the projector's brightness and other settings which helped a little, but not by much. 

I did a quick comparison of the two light sources just to see home much energy the new LED saves. The 265 watt bulb used 0.265 kWh in an hour while the 20 watt lamp only used 0.02 kWh, about 13 times more efficient. 

Step 5: Building the New LED Light Source: LED V1.1

Picture of Building the New LED Light Source: LED V1.1

I decided that a reflector and a lens could probably help focus the wide angle of the LED. I used Google Sketchup to do the math and made a template that I could then use to make the pieces out of aluminum sheet metal. I found a lens that focused the most light and fit within the reflector. 

I'm sure that this could have been made way better and more mathematically, but at the time I did not know the math or the physics to do so. The hardest part about using this type of LED is trying to focus 20 individual light sources, each one with its own focal point. 

This modification actually helped a lot. The picture was much brighter and you could actually watch a movie on it, but I still needed to have all the lights off and the darker scenes were still hard to see. 

Step 6: Building the New LED Light Source: LED V1.2

Picture of Building the New LED Light Source: LED V1.2

For the next modification I tried actual mirrors for the reflector rather than the dull aluminum. This made the picture even brighter and easier to see, but again it still was not bright enough to enjoy a movie. 

Step 7: Building the New LED Light Source: LED V2.0

Picture of Building the New LED Light Source: LED V2.0

I did not use the projector almost all summer and I was disappointed that I couldn't get the LED light focused more. I was browsing around on eBay in the fall and I came across a 100 watt, 8000 lumen LED for $60. It came with the LED driver, lens, and reflector. I thought about it for a while and did some research about the increase from a 20 watt LED to a 100 watt LED. There would be a substantial increase in heat that this new LED would produce, but since the original bulb was 265 watts i figured that the fans and the heat sink would be able to handle the heat. 

I bought the LED and it arrived later that month. Changing the LED was not too hard at all. the new LED had the same mounting spots as the last one. All I had to do was take the old one off and put the new one on. I soldered the new power supply, and glued the lens and reflector to the LED. 

I was sure that there would be a huge increase in the picture brightness going from a 2000 lumen LED to an 8000 lumen LED, and I was right. I was able to see the picture even with the lights on. when I turned the lights off the picture was just right. Bright enough to watch a movie. The only concern that I had was all of the heat that the new LED was producing. I ran the projector for 30 minutes and then let it cool down; then an hour and finally for three hours. From these tests, I found that the heat sink and the fans inside the projector were enough to keep the LED from over heating.

I did another comparison of the two light sources. The new 100 watt only used 0.1 kWh in an hour and would cost only 1.2 cents per hour. Again, the 265 watt bulb used 0.265 kWh in an hour costing 3.18 cents per hour, 2.65 times more efficient. 

Step 8: Finished So Far

Picture of Finished So Far

As for now the projector is finished until I get another idea to improve it even more. Over the whole project I spent about $100 on LEDs and other materials and it took almost two years to complete. It is bright enough to enjoy a movie and I am satisfied with the control of the heat. I'm sure a few years down the road there will be better LEDs that will work better for this project, but for now it is good.


DavidS1545 (author)2017-10-09

I'm gonna need some help with this

pin1 is at 12.6V at startup for aprox 3-5 seconds

pin2 sits at 3.3V

pin3 stays at 0v (this one presumably gets a signal from the ballast if the light fails to strike so the projector will set the error lights appropriately)

pin4 stays at 12.6v for a couple seconds then goes to 0v and jumps back up to 12.6v after aprox 5 secs

I need to figure out how to convince the projector that there is a good bulb

DavidS1545 (author)DavidS15452017-10-09

unless I have the pins reversed

I just realized that I think pin 1 is the yellow wire....................not the brown wire like I thought

that would explain what I thought was pin 3 being at 0v (ground)

still what should I try? pin one to ground?

mcaskey1 (author)2017-02-24

Anyone doing this with a Panasonic pt-ae1000u?

FadiR1 (author)2017-02-22

Best way to do a bypass would be to buy one of these cheap chinese bulbs (you know, the ones that burn out in a month and are dimm as sh*t but cost 20$ instead of 300$). Those things are made of A the bulb and B the bulb's circuitry. Bulb's circuitry is what sends the ok to your projector. If you can find a way of taking out the nasty bulb while keeping the circuit active, you have yourself a bypass at no risk to your projector. At 100W for the LEDs, you may even be able to use the projector as a powersource if you can figure out what to do with the excess power.

dom_i_nick (author)2015-03-28

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 :-)

AnthonyF30 (author)dom_i_nick2015-12-03

all you need to do is locate the optocouplers and short each side of it until the light stays on. on my epson i had to short the top optocoupler. all i did was drop a bead of solder on the pins on the right side of the optocoupler (The Switching side) though yours may be in a different location

dom_i_nick (author)AnthonyF302016-09-26

Thanks. I gave that a shot but it didn't work... I did some more research with the manufacturer and apparently serial communication is *optional* but it looks like Dell went that route.

Like psron said, below, there's not really a way around that.

WirelessGuyN (author)dom_i_nick2016-09-19

Did you ever figure this out?

psron (author)dom_i_nick2015-10-11

Unfortunately, this appears to be one of the projectors that uses serial data to communicate to the ballast... the boards actually talk to each other, exchanging data.

There's no easy way to bypass that one...

gomme600 (author)dom_i_nick2015-04-15

Just a tip you might want to use a brighter led as there is a lot of loss inside the projector.

KENNYJ9 (author)2016-08-12

This gives me hope. For year I've been thinking of this very same project. Next I'd like to know is there way to upgrade the Resolution? He he he

ulfilas (author)2014-11-03

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?

psron (author)ulfilas2015-10-11

There's no way (DIY-way) to combine the multiple LED's into one single-point-source... which is what's expected for projector light sources. The arc-lamp reflector creates a single-point light source, which is easy because it starts with a single point light source... an electrical arc. Using large, multiple-emitter LED's will result in horrible efficiency. Single-large emitters can be focused, and can result in higher efficiencies, to where a 10W single-chip LED may work far better than a 100W LED that used 100 chips. Look for large-single-die (single-chip) White LED's.

rajivshahi (author)ulfilas2015-01-18

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

CaseyS2 (author)2015-01-22

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.

psron (author)CaseyS22015-10-11

No DIY LED conversion will result in a brighter image than the original arc lamp... those lamps typically have 20,000 to 50,000 lumens output from the reflector. Projectors are VERY lossey... often less than 10% of the lamp brightness comes out the front of the projector.

ronit suryavanshiu (author)2015-06-04

any help with infocus 425z dlp projector. it have ps and ps control board sold and mother board connect through pins on ps board.

hope to see something from you soon:)

psron (author)ronit suryavanshiu2015-10-11

There appears to be two (2) signal paths to/from the ballast... a "Lamp Enable", and "Lamp Lit". Each of these will go through an opto-isolator. The "Lamp Lit" will be sending signal to activate the opto-isolator Output that tells the system it's OK to operate. So, if you can determine which one is the "Lamp-Lit" opto-isolator, and find the datasheet for that part, you can connect a wire across it's Collector and Emitter output pins.

SeanS17 (author)2015-08-12

For all of you that are stuck.... instead of bypassing the lamp cant you just create a dummy load where its on but doesnt actually get to light things up. Then just make a separate connection to the new light source altogether externally? And as far as improving the design couldnt we take it out of its original shell and make a new one where it has more room to breathe and then we could add even more led power using two of the 100 watt ones like the 3d design on this site but not 3d?

psron (author)SeanS172015-10-11

Creating a "dummy load" for an arc lamp is a very complicated thing... and it would need to dissipate 150 to 300 Watts... sometimes more.

One problem is that some newer projectors use data communications tot he lamp ballast/supply... so there's no "easy" way to bypass the 'intelligence'. IT used to be very simple... no so much now.

gomme600 (author)2015-03-21

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!

psron (author)gomme6002015-10-11

No, that power supply does not have "CC" mode... Constant Current.. also known as Current Regulation. You need a "CV/CC" mode power supply with both adjustable Voltage -AND- Current.

Without the LED connected, set the Voltage to at least the maximum rated voltage, but set the Current to the lowest level. Then after connecting the LED, slowly increase the Current until it's a little less than the Maximum Rated LED Current. You must have an accurate DC Ammeter connected in series with the LED to measure Current.

WARNING! If you run the full rated Current to the LED, it will get INCREDIBLY HOT... even with a huge heatsink. Unless you run liquid cooling, I recommend running no more than 70% rated current, and you will STILL need a huge heatsink, and forced airflow.

Lord AntonH (author)2014-12-16

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.

ánagy10 (author)2014-06-14

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?

Velvelkjell (author)2014-05-08

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

liam2317 (author)2014-04-18

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!!

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!

asantos5 (author)2014-01-01

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...

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...

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

sk8er6 (author)2013-11-11

Great job breaking down the bulb bypass. Trying to get started on mine today.

roelvdm3 (author)2013-02-22


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

kind regards

Both LEDs that i bought came with DC drivers. I did not want to mess with the high voltage AC from the projector.

dtommyd (author)2013-03-18

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.

I have found that with the LED that i have the picture has a slight yellow tint, but it is not to bad.

redshift (author)2013-09-15

"LED Engin's"
Total Internal Reflection (TIR) lenses for die emitters...

bogdanvitelaru (author)2013-04-12

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!

joshvonnieda (author)2013-01-02

Did you use a bright white LED? I've also seen warm white. Wondering if this color temp may be more suitable.

joshvonnieda (author)2012-12-31

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?

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.

joshvonnieda (author)2012-12-30

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.

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.

claudiopolis (author)2012-11-27

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 :-)

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.

biolethal (author)2012-11-26

Very nice! voted.

biolethal (author)biolethal2012-11-26

*meant to vote, but it doesn't look like it's entered in any contests right now...

I just submitted it. It is probably still going through review for entries, but thank you.

About This Instructable




Bio: I am currently in college and I love building things in my free time. Whether it is to save some money by making a clone ... More »
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