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
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.
WHEN CUTTING AND TYING THE WIRES TOGETHER MAKE SURE TO CUT A COUPLE INCHES AWAY FROM THE CONNECTOR. THE WIRES SHOULD BASICALLY BRIDGE THE CONNECTOR. DO NOT SIMPLY CUT THE WIRES OFF OF THE CONNECTOR. ON THE OTHER HAND, THE ORANGE WIRE NEEDS TO BE CUT OFF OF THE CONNECTOR.
Step 2: Bypassing the Bulb Checking Circuit: More Research and Tests
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
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.
AGAIN: WHEN CUTTING AND TYING THE RED AND BROWN WIRES TOGETHER MAKE SURE TO CUT A COUPLE INCHES AWAY FROM THE CONNECTOR. THE WIRES SHOULD BASICALLY BRIDGE THE CONNECTOR. DO NOT SIMPLY CUT THE WIRES OFF OF THE CONNECTOR. ON THE OTHER HAND, THE ORANGE WIRE NEEDS TO BE CUT OFF OF THE CONNECTOR.
Step 4: Building the New LED Light Source: LED V1.0
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
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
Step 7: Building the New LED Light Source: LED V2.0
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.