Bell and Howell 1598, User Manual

Page: 29 / 38

P a n chromatic TQIII & TQIII Specialist User Manual
Page
29
Replacements
51
Projection Lamp . No light on the screen, when the projector is otherwise functioning normally,
indicates that the projection lamp has failed. Set the main power switch on the non-operating side
of the projector to off". Open the main access door.
Alongside the loudspeaker in the side cover are spaces for storing a spare projection lamp, a spare
exciter lamp and spare fuses.
Because lamps fail without warning, it is advisable during a
presentation to place spare lamps (EM M, or Al /258) near to the projector ready for immediate
use.
52: Remembering that if the lamp has just failed it will be hot, disengage the retaining clip 52a by
firm downward pressure and leave it hanging free.
53 Grasp the failed lamp as shown and pull it directly towards you out of its sockets. Holding the
replacement lamp in a clean cloth, insert the pins of the lamp in their sockets- taking care not to
touch either the reflector or the bulb and push the lamp as far towards the projector as it will go.
If either the reflector or bulb is touched with bare fingers, apply household alcohol with a fluff-
free cloth to remove any contamination and allow to dry.
54 Grasping the retaining clip and lamp base between finger and thumb raise the clip until it clicks
into the notch in the lamp base.
55 Close the main access door, set the main power switch back to "on' and Continue projecting.
56
Exciter Lamp . If the projector is otherwise working normally but there is no light behind the red
window in the exciter lamp cover, the most likely cause is a failed exciter lamp. Pull open the main
access door and set the main power switch to "off". Unscrew the securing knob 56a and, taking
care not to strain the film with the edge guide 56b, lift the cover away from the projector.
57 Push the exciter lamp securing lever 57a towards the projector to free and raise the exciter
lamp. Rotate the lamp until the three slots in its ring can disengage from the studs on the
projector and remove it.
58 Fit the ring of the new lamp over the three studs - there is only one position in which this can
be done - and rotate the lamp until the studs are at the narrow ends of the slots in the ring. Pull
the securing lever 58a all the way back to its running position. Replace the exciter lamp cover,
reset the main power switch to "on" and close the main access door.
59
Main Fuse . The circumstances in which the main fuse may need to be replaced are explained in
Stage 32j. Set the main power switch to "off" and remove the power lead from the projector
socket. Unscrew the fuse holder 59a with a coin or screwdriver and pull it out, subsequently
pulling the tubular fuse 59b from its clip in the holder. Replace with a fuse of the thermal or surge-
resisting type (normally marked 4AT or T4A on one of the metal caps 59c). Screw the holder back
into its socket, connect the power lead and set the power switch to "on". If the replacement fuse
fails quickly, do not fit another. Ask your audio-visual dealer to investigate.