8mm Forum: Elmo GS-800 Stops

This is topic Elmo GS-800 Stops in forum 8mm Forum at 8mm Forum.

To visit this topic, use this URL:
https://8mmforum.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=008793

Posted by Maurice Leakey (Member # 916) on December 09, 2013, 02:27 AM:

Whilst running my Elmo GS-800 (bought from a well-known fellow member) it just stopped and immediately the film frame started to burn. I switched to OFF and then after a few seconds to F and then lamp. It then quite happily ran for the rest of the film.

I checked the motor drive belt which appears to be quite OK, perhaps there is an intermittent electrical fault somewhere.

It's been in use for six years. Has anyone got any ideas as to the problem?

Posted by Paul Browning (Member # 2715) on December 09, 2013, 05:43 AM:

Hi Maurice, I had st800 that did the exact same thing, I know its not the same model but just check the main push on cables to the largest board in the back, the solder fractures on these connections so the plug to them becomes temporarily disconnected electrically so to speak, you will need a good magnifying glass and be competent with the old soldering iron, certainly fixed mine, never stopped again. Good luck.

Posted by Maurice Leakey (Member # 916) on December 09, 2013, 09:47 AM:

Paul
Do you refer to the flying leads connected to the plugs, perhaps with dry joints where the wires terminate at the plugs?
Or, do you refer to the pins which are on the board, probably soldered below onto the PCB?

Posted by Paul Browning (Member # 2715) on December 09, 2013, 10:13 AM:

Hi Maurice, Sorry, just to clarify, where those plugs push onto the boards, the pins making the connections which are soldered onto the PCB, check those soldered joints under side of the board, they do go dry jointed and crack around the joints, making and braking the connections as the board is moved around within the fixing. Its not that obvious when you look at them either, I generally remove all old solder too, this way you will get a fresh clean re-soldered joint.

Posted by Maurice Leakey (Member # 916) on December 09, 2013, 10:25 AM:

Paul
Many thanks. I suspect that Elmo used poor quality solder. My service engineer had to virtually re-solder nearly every connection in and around the amplifier on my GS-1200.

Posted by Paul Browning (Member # 2715) on December 09, 2013, 10:48 AM:

Maurice, you maybe correct about the solder used, however it reminds me of a story an ex Sony TV engineer once told me. To cut costs Sony sent some of there boards to mainland china to be soldered, mainly the portable Trinitron model they made, however because of the poor quality of workmanship almost everyone of those TV's returned to Sony repair shops in the UK for rectification( resoldering of the whole board). I wonder if Elmo did the same to cut costs, I would not be surprised.

Posted by Terry Lagler (Member # 1110) on January 22, 2014, 01:36 PM:

I have a new ST800 in wonderful cosmetic condition. Just put in new belts and ran a few hours of film before I had the same problem Maurice had. The projector just stops but the lamp remains on. Starting and stopping usually fixes the problem but it eventually happens again. I've taken a look at solder points and everything looks good. Do you ever come up with a solution for your GS 800?
Cheers
Terry

Posted by Maurice Leakey (Member # 916) on January 22, 2014, 02:07 PM:

Terry
My GS-800 will be taken to my service engineer this coming Sunday. I will report on this Forum in due course his findings. This may take some time as there are also four other projectors going.
Three of the five are Elmos. GS-800, GS-1200 and a 16-CL. Are Elmo projectors not manufactured as well as other makes? My various Elmos go for repair at much more regular intervals than my other makes of projectors.
Or am I just unlucky?

Posted by Terry Lagler (Member # 1110) on January 22, 2014, 02:14 PM:

Best of luck with your Elmo's Maurice. In the meantime maybe I'll poke around a bit more. My Eumig S938 is still the projector of choice so the ELMO can go on the shelf for the time being.
Cheers
Terry

Posted by Steve Klare (Member # 12) on January 22, 2014, 02:22 PM:

I could imagine this being a problem with the switches that control the motor. There is a cam turned by the selector knob that pushes on snap switches. These do things like controlling the lamp and the motor too.

There should be two switches for the motor: one on each terminal. Each selects either (+) or (-) motor voltage and they choose the opposites of each other when the motor is operating so the transport direction can be reversed. It all depends on which switches are being depressed by that cam at each selector position.

If either switch was flaky, I could imagine the motor stoppng at odd times, and the switches are more than 30 years old now.

The switches are commonly available (Radio Shack has them...). They are a bear to replace (I've done it: it's doable. Send the kids outside, have a beer afterwards.) and you should be reasonably sure this is the problem before you start surgery.

Could be the motor too.

Either way you need to see what's up with the voltages in there when things go wrong.

Posted by Paul Adsett (Member # 25) on January 22, 2014, 07:03 PM:

I think the case can be made that Elmo's have more problems than Eumigs. My two GS1200'S both need periodic repairs of one kind or another, particulary switches and relays. IMO the GS is probably too complex for its own good. A case of the more bells and whistles you have, the more to go wrong.
On the other hand I have never had to do any electronic repairs on any of my many Eumig projectors. Eumig electronics seem to be utterly reliable, and they seem to have used top quality soldering on their circuit boards. And my Eumig lenses have not fogged up like some of my Elmo lenses have, so Eumig apparently used higher quality optical coatings than Elmo.
Eumigs designs are simple (in a very brilliant way) compared with the complex Elmo's, and simple is good.
Please excuse my obvious bias! [Big Grin]

Posted by Lee Mannering (Member # 728) on January 23, 2014, 02:44 AM:

Never had any solder electrical problems on a GS1200 and have had quite a few over the years. You many need to go to a film fair and search for spare parts Maurice in person?

Bill Parsons is an excellent service chap on Elmo machines, a gentleman and a marvellous help. Boy we are lucky to have him in the UK. All projectors are a bit like cars being mechanical not digital and it does amaze me how many just keep on running any machine without cleaning the gate never mind sending a projector away for a service every few years.

Yup the good old Eumig machines were designed by a company given birth in 1920 so plenty of experience and know how to come up with a compact portable movie projector in simple design. You never stop loving the little Eumig..

Posted by Terry Lagler (Member # 1110) on January 23, 2014, 07:56 AM:

Steve, I'm assuming to get at these switches that control the motor this front plate must come off.I've located 4 screws on the underside and 1 on the top (red arrows show location) I can pull off the selector knob and it looks like I'll have to remove the volume know too.
Never removed this part on any Elmo before - is this the correct place to check?

Cheers
Terry

Posted by Steve Klare (Member # 12) on January 23, 2014, 08:25 AM:

Hey Terry,

Actually you get to them by removing the back cover.

There's a stack of insultors, switches and steel plates surrounding the main control shaft and secured to the chassis by long screws.

You should be sure you want to replace these switches before you take this apart: there are a lot of pieces to manage! (I can tell you how.)

If you are good with a voltmeter your first step is to find points to measure the switch voltages. If you aren't then your first step is to become good with a voltmeter!

Posted by Terry Lagler (Member # 1110) on January 23, 2014, 08:32 AM:

Thanks Steve, very helpful.
Looks like I'll have to put a day aside if I want to tackle this! And find my voltmeter! This will have to go on the backburner for now but at least I know who to go to.
Appreciate the help.
Terry

Posted by Steve Klare (Member # 12) on January 23, 2014, 09:22 AM:

My experience with this is equal and opposite to yours.

My ST-800 had trouble about 5 years ago of the lamp staying on after I stopped the machine. That problem turned out to be the snap switch for the lamp sticking "on" when it should have switched to "off".

In hindsight I should have replaced all three switches while I was at it, but I wussed out and did just the one for the lamp.

-been OK ever since though.

Posted by Maurice Leakey (Member # 916) on February 19, 2014, 03:32 PM:

My engineer has just 'phoned to say he has found the problem with the motor stopping. As expected with an Elmo, it's a dry joint.

The dry joint is on the pcb motor speed control section where an orange plug/socket emits two wires which go down into a loom. The wires are one white, one grey.

The actual joint is the last one. As the plug/socket is quite large and on the end of the board it could quite easily get a gentle knock if the rear cover is not carefully re-attached.

UBB.classic^TM 6.3.1.2