8mm Forum: Elmo ST1200 Optiacal/Magnetic Sound Problem... HELP... Please

This is topic Elmo ST1200 Optiacal/Magnetic Sound Problem... HELP... Please in forum 8mm Forum at 8mm Forum.

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Posted by Ian John (Member # 507) on February 20, 2011, 03:05 PM:

Hi Guy's,

I have just bought an Elmo ST1200 projector privatly, and after paying for it and having it sent, when it arrived, I discovered it was the Magnetic & Optical model (with the round plug mains lead), which I was over the moon to disscover, as there was no mention of the optical sound from the lady I bought it from, I thought I was buying the mag only version. The other thing I was pleased about, is the fact it came with Elmo's f1.1 lens.
To all intents and purposes, this projector looks Factory fresh, unused, all items in elmo black case Brushes, Earphone, Microphone, mains lead Etc are still in sealed plastic bags, and the User manual is new unopened, the projector still has it's original lables attached to a bit of purple ribon fixed to the handel, and interior and exterior of carboard box is brand new.

Now my problem. Can I start by asking a few questions to any sound techs who know this machine. Does the magnetic sound side of this projector use the same amplifier circuite as the optical sound, and michrophone side of the projector?

When I powered the projector up for the first time there was no magnetic film sound (the switch was at the mag postion), but when mic was plugged up, the mic sound came out the speaker. I have no optical sound film to try the optical sound, but when moving a bit of thin card between the exciter lamp and pick-up, I could hear the popping sound, so, this stage I got to thinking that if the op side of the machine is using the same amplifier, then prehaps it's not the amp at fault, but somthing more sinister has gone wrong. Any surgestions on what to look for, or any possible ideas on what has gone wrong? Does this sound like an expensive repair job/service? I am no good with multi-meters etc, but can do simple fixes.

The othe things that I noticed is, the rewind is very, very, sluggish, moves very slow then stops, and is difficult to engage first time. When switched into forwad or reverse projection, I have to ingage the switch with more presure than normal to get the projector to start properly, and the speed-change switch is stiff and don't seem to engage 100%, I have to push it to engage it. With the back off, the rubber rollers don't seem to engage the side of the shutter wheel properly.

I just don't understand all this, in a projector that is factory fresh, does not show any signs of a film ever being run through it, spotless rubber pinch roller, spotless film guides and rollers, and spotless gate etc.

Sorry this seems a long thread, but ried to explain the best I can. I would appreciate any help from any of you Elmo Lads who has worked on these lovely machines. Thank you so much.

Ian.

Posted by John Skujins (Member # 1515) on February 20, 2011, 07:58 PM:

If the projector is mint and unused, then it has its original belts of course. I'm no expert on Elmos but from reading this forum I've learned that a lot of original Elmo belts have turned to "goo." That might explain the sluggish rewind. I have no idea about the sound issues, anyone else?

Posted by Ian John (Member # 507) on February 21, 2011, 08:58 AM:

Hi John, Thanks for your input, I would agree with you that the original belts might of turned to goo by now, I have had the back off the projector, and the one belt I can see, like a "V" shape (which runs around the speed-change rollers seem to be in good nick, but I have no way of telling whether or not it is the original belt, but I will get a spare set of belts for the projector, just to eliminate that side of things being a possible cause of speed-change and rewind problems.

I would also like to try and get the magnetic sound problem solved, if I can.

A couple of the nylon gears have grease on them, which seems to me to be ok (not dried out), but all of the other smaller nylon gears seem to be very clean, with no sign of grease ever being on them.

What is the best grease to apply to these gears? because some grease and oils can draw out the plasticizers in the nylon the gears are made from.

I have white lithium grease (arisol type sprey), and a bottle of German "Projektoren oel Type 3672/00" (projector oil) which is used on cinema 35mm projectors, but I don't know if it would be safe to use any of those products on this Elmo, any further advise would be apreciated on that.

Ian

Posted by Douglas Meltzer (Member # 28) on February 21, 2011, 10:54 AM:

Hi Ian,

Congratulations on getting an M/O model with a 1.1 lens!

With the M-O switch set to M, is there any speaker hum when you turn up the volume control knob? It seems like the amp assembly is fine if the Record & Optical modes work.

Does the sound head appear to be making contact with the mag stripe while the motor switch is in the forward position? The head can get out of alignment.

Did the magnetic sound film you tested appear to be running at the correct speed?

Just checking....after setting the motor switch to the R position and pushing down on the rewinding lever, the reel starts to rewind and then stops?

For grease recommendations, check out these posts:

Post 1
Post 2

Doug

Posted by Ian John (Member # 507) on February 23, 2011, 02:01 PM:

Hi Doug,

Yes, it was a very pleasent suprise to discover the M/O had a 1.1 fitted to it, I was expecting the 1.3 lens to be on it.

As for the M/O switch set to mag position, there is no response at all, no hum, hiss, nothing. The only thing I tried as far as record was concerned, was pushing in the record button on the rear, with the microphone plugged up, and the sound did come through the built-in speaker (basically like a P.A.), but a record test to film soundtrack was not attempted.

In my mind, I think the amp is ok, and it might be something like a broken solder/wire, or a short of some kind that is preventing the mag side from working. The speed of the films I tested on it looked fine to me.

I checked the sound heads while the projector was in "R" position, and while film was running, and the heads seemed to align on the track of the film fine, as normal, but I hear what you are saying, the heads can somtimes go out of elignment.

When the machine is switched into the "R" position, and I engage the rewind switch, the reel starts to move, then slows down for a while, and comes to a halt, and there is a bit of a rattle noise that comes from inside the projector, I then shut the machine off.

I happen to have some airosol White Lithium Grease Sprey, which I sprayed onto a bit of cardboard, and then very, very, thinly applied a very small amount on a Q-Tip onto the gears, including the worm gear, and made sure I kept it away from anything rubber, including belts/shutter wheel/Rubber drive rollers etc.

Since your post, I have spoken to another member of this forum Bill Parsons on the telephone, and he is willing to take a look at the projector for me, so I have parceled it up, and sent it up to him to have a look at. I gather from reading other remarks on this forum, that Bill is a top surgeon in making Elmo's better, and after talking to him on the phone, he certainly came over as a nice guy, and a knowlegable man on the subject of Elmo's.

I am looking forward to hearing the outcome from Bill right now, an see what his opinions are on the projector.

Ian.

Posted by Nick Field (Member # 2132) on February 23, 2011, 02:09 PM:

I have the same problem with my st 800 with no sound but the record does'nt work either so i'm thinking mine is an amp problem,i need to get in touch with Bill to see if he could look at it for me too.

Posted by Steve Klare (Member # 12) on February 23, 2011, 02:46 PM:

I had no sound on my ST-800 a few years back. There is a small circuit board mounted beneath the framing knob that has wires from the heads surface soldered to it and one of the bonds had broken leaving the heads open circuited.

-a little touching up with an iron and solder would fix this.

(Worth looking into at the least.)

Then there is always the the record key trick. I've lost sound several times only to have it brought back by working the record key a few times. (audio jacks can do this too...)

Posted by Nick Field (Member # 2132) on February 24, 2011, 01:23 AM:

Tried all of the tricks unfortunatly none of them worked, I think it may be in the pre amp circuit which is in the front of the projector, Theres no hiss when the volumes turned up to max but there is a pop when i turn on the amp with the volume contol and the vu needle fluctuates. [Confused]

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