Cheap projector bulb replacement
Replacement projector bulbs cost $150, or $250, or for my ancient out-of-production 3M MP8650, $1000! Recently I bought a Compaq MP1600 on craigslist for $15, but it needs a $250 bulb. This kind of investment is more than the projector is worth, so what do you do?
When you buy a new projector bulb, you're actually buying a whole assembly that usually includes a bracket, a reflector that fits into the bracket, wires and a plug, sometimes a chip that counts the hours on the bulb (avoid these projectors!), and the bulb itself. Here's what the MP8650 bulb assembly looks like:
These cost so much simply because the assembly is out of production. They're scarce, so sellers can charge what they want. But really, when you replace the bulb, this is the only part you need:
Below is a procedure to replace the lamp using your existing assembly. I did this, and so far it's working for me, and it's working for many other users in the following link.
Here's the thread where I first learned about this. A fellow in Guangzhou, China, named Yu Weihua, aka "YWH", at firstname.lastname@example.org, gets the bulbs directly from the factory in his city. He has been doing this business for several years now, and I believe he is quite reputable. They usually cost $45 for older, larger projectors, or $89 for newer, smaller ones. You have to figure out what kind of bulb you need, then send him the money through Paypal, and a couple of weeks later you'll get the new bulb in the mail. Then it is up to you to disassemble the bulb assembly, scrape out the cement that glues the bulb into the reflector, and cement the new bulb into the reflector. This can be difficult to do and I believe YWH is willing to do it for you if you send him the assembly and the money; please ask him. However, most people on the diyaudio forum attempt to do it themselves, as I have done.
Collect the following pieces:
- The old bulb assembly. Look in your projector's user guide for how to remove it.
- A new bulb from YWH. You can try searching the thread on diyaudio.com to see if someone has already identified the bulb in your projector. However, this is not perfectly reliable, since YWH's replacement bulbs change sometimes. Mainly, you need to know if the bulb is AC or DC (find this in the thread, or look at your old bulb: if the electrodes are different sizes, it's DC; if the same, AC); and the wattage (check projectorcentral.com for your model). YWH can help you with this.
- Some latex gloves. If you use the cement I recommend below, it is caustic. Also, you must avoid getting fingerprints on the new bulb, or its life will be shortened.
- Furnace cement. This is basically high temperature cement. I found some at the local Ace hardware store (see pic below); it's too soon to know if this will work well, but so far so good.
- Screwdriver and other tools to disassemble the lamp assembly.
- A marker to mark the bulb
- Tools to scrape out the old cement, such as dental picks or tiny files.
- Q-tips and water to help clean up the cement after application.
Before doing anything else, it might be wise to put some foil or something over the middle of the new bulb so that you don't get any fingerprints or cement on it. Anything you get on the glass will absorb light, which will heat up the glass and shorten the bulb life.
Also, put on your gloves.
Mark the position the old bulb is installed in. I marked the level of the end of the reflector, an easy reference point. You need to get the arc of the new bulb installed in exactly the same position as the old, so this is very important.
Use your pick or files to carefully remove the cement holding the old bulb in the reflector. Some reports say that soaking the cement in water helps. Be patient, and be gentle!
You can see in this pic that my reflector has some cracks in it. This probably happened when the old bulb exploded. These points are extremely weak, so don't put any pressure on the reflector. I actually broke my reflector, and had to glue it back together. I hope that superglue can withstand the heat.
When you have the old bulb out, put it next to the new bulb and transfer the alignment mark to the new bulb.
Here is the cement I used. The jury's still out on whether it's good stuff, but I got it at the local Ace Hardware for $4. I figure there's enough for about 300 bulbs.
This stuff is pretty easy to work with. You can roll it into little balls and squish it into the cracks between the bulb and the reflector. It's water based, so you can use Q-tips and water to clean up after your mistakes. Be careful though; the instructions say that if you let it dry on the glass, it won't come off.
Here's a really blurry shot of getting ready to squish a ball of cement into the reflector.
A shot of the finished cement job. Also you can see the wire from the other end of the bulb is attached to the terminal. The old wire was spot-welded in place. I simply removed the spot weld, and the new wire just clamps under the screw with the wire from the plug.
Here's what the inside of the reflector looks like. I did my best to clean up the cement.
If you look carefully, you can also see where I split the reflector in two. After the initial cracks from the bulb blowing, it was just too delicate.
The reflector with wires attached from the outside. The cracks are especially visible here.
The assembly all back together.
Be careful disposing of the mess. The old bulb has trace amounts of mercury in it, and should be disposed of properly (tm). Also, the cement is caustic before it dries, so be careful with any mess you made.