This procedure refers to several different models of overhead projector. The distinction between models generally refers to the lens focal length, and whether or not the projector has a lamp changer. In addition, the Bell & Howell projectors (green cases) use DYS-type lamps while the Eiki projectors (black cases) use EYB lamps. The lamp replacement procedure is nearly identical in all cases.

Relamping Procedure

CAUTION:Before opening the housing and replacing a burned-out lamp, be sure the lamp has cooled thoroughly. Unplug the power cord if possible before changing the lamp.

Opening the projector

Begin by making sure that the power switch is turned off. A mechanical interlock prevents the case from opening if the power switch is not turned off. Next, push in on the lock lever and move it down to the UNLOCK position.

Now lift up on the front edge of the stage glass housing. The entire upper section of the projector will hinge open, revealing the innards of the projector.

Removing the burned-out lamp

Inside the projector you will find one or two lamps (depending on whether or not the projector has a lamp change lever). Wide angle projectors with lamp changers have an extra non-removeable lens over the lamp. You may need to shift the lamp changer in order to get access to the burned-out lamp.

For projectors using DYS lamps: The lamp socket is equipped with a lamp ejector. Push the lever towards the socket base to force the lamp out of the socket. Note that the pins of the lamp are different sizes...take note of which pin goes into which hole so that you can properly install the new lamp.

For projectors using EYB lamps: The lamp socket is not equipped with a lamp ejector. Grasp the ceramic base of the lamp and pull it away from the socket. It does not matter which side of an EYB lamp faces up, consequently the pin orientation is not critical so long as both pins plug into the socket.

Installing the new lamp

Important: For optimum lamp life and performance, do not touch the quartz (glass) bulb of the lamp. The oils in your skin will attack the quartz and cause the lamp to fail prematurely.

The lamp comes in a sealed plastic bag. One edge of this bag has a perforation on it. With the lamp still in the plastic bag, grasp the ceramic end of the lamp just above the pins, and tear the perforated end off of the bag. Manipulate the lamp so that the pins protrude through the open end of the bag. With the lamp still in the closed end of the bag, line the pins up with the socket inside the projector, and push the lamp into place. If you are having difficulty inserting a DYS lamp, try turning the lamp over, as it will only fit into the socket one way. Once the lamp is fully seated in the socket, completely remove and discard the plastic bag.

Closing the projector

Close the projector by pushing down on the stage assembly, then moving the locking lever up to the locked position. Make sure the projector is plugged into an electrical outlet, and test it by turning it on. It should light up. If the projector is equipped with a lamp changer, turn off the power, switch to the spare lamp, then turn the power back on to check the spare lamp. Both lamps should be working. Turn off the power and reset the lamp changer (if present) to the main position. Your work here is finished!