This is for a friend of mine who i am hoping will join us here very soon!
It is the procedure required to completely change out the existing lamp holder and exchange it for an identical new one on a Beaulieu 708el CD Super 8mm projector.
The model featured is a Stereo model but the same procedure can be used on any of the range of models out there except the HTI.
1/ Remove rear cover and speaker(s) cables noting polarity when doing so.
2/ This is how the machine should look once doing so and have it positioned as the photo suggests preferably at chest height on a projector table.
3/ The lamp holder is wired directly to the the transformer 15vac tapping on one side of the circuit, and then through the main switch on the other.
to gain suitable access to the mechanical main switch mechanism, it will be necessary to remove the main motor and the Main supply terminals to it only.
First you need to remove the motor fan cowl to gain access to the motor fan etc.
It is held on to the main casting by 4 screws. The top two screws can be seen here. the Bottom is a repeat of the Top.
Completely remove the fan cowl noting orientation once screws have all been removed.
4/ Remove the main motor drive belt. This is very easy to do on these machines as there is sufficient clearance in the body of the projector to allow this to happen.
5/ Remove the main Motor cables. Note Polarity! Red cable to the inside terminal, Black cable to the outer terminal.
Do NOT attempt to de solder the two small White and Blue tachometer cables. This is unnecessary work and doesn't need to be done to complete this particular job successfully.
Now remove the main motor (two screws top and bottom) and rest it on top of the transformer, take care not to pull on the delicate Tachometer cable joints. (see next photo)
6/ Now you should clearly be able to see and access the Main Switch contacts. This switch is an electro- mechanical device that uses a Nylon Camshaft from the main switch Knob to bring in all of the electrical devices into circuit as and when they should in accordance with the main switch knob markings.
By pulling on both of the existing lamp cables from the lamp holder, it is possible to see whereabouts they are terminated even without the service hand book.
One side of the lamp holder terminates via a female spade connector (readily available), with a contact terminal from the main switch commutator.
By gently pulling each of the existing lamp leads while carefully observing the terminals and cables for movement, it should easily be deduced which spade connector and terminal is for the supply to the lamp.
See PI 8 of the service Manual (if available) or photographs below:
7/ It may prove necessary to extend this particular new Lamp Holder cable in order to reach the switch contact position comfortably. in this case, extend one side of the new Lamp Holder cables by soldering a length of similar rated cable to the bared end of the new holder cable prior to attempting to fit
Note. Always completely cover any soldered joined length of cable using heat shrink with the aid of a heat gun to ensure a professional and safely insulated connection is made.
8/ Repeat step 6 for the other lamp holder lead, this time going to the transformer tapping. This cable SHOULD NOT need lengthening even if the other cable may in some cases prove to be slightly too short.
refer to the schematic drawing for the exact reference point of the terminal positions on both the switch commutator and the transformer.