Posts: 720
From: Worthing, West Sussex, UK
Registered: Feb 2009
posted April 17, 2016 08:25 AM
So, I'm looking to get this Elmo HiVision SC18 back up and running because I have quite an affinity for them, it was the first projector I truly desired when I was about 14 but could never afford one! I picked this one up from Mr. Guest last week and I'm ready to get to work on it, but what on earth is this modification supposed to be? I'm wondering if it was some sort of sync unit connection? Anyone throw any light on it?
So as you can see, there's a male 2 pin plug which has been soldered to the PCB above the mains transformer, and a matching female connector directly soldered to the internal speaker. I haven't powered the machine up yet as I wanted some advice and ideas first.
EDIT: This has also been fitted with a 24v 200w bulb, not a 12v 100w as per the usual spec.
Posts: 7016
From: Long Island, NY, USA
Registered: Jun 2003
posted April 17, 2016 11:47 AM
The black plug looks like some kind of power connection, given the style of the wiring and connecter and the fact that it's running up to a fuse panel.
It could be associated with the lamp swap: maybe this is how you choose the lamp voltage, then again that socket connected to the speaker deepens the mystery.
-it's almost as if there is some piece missing in the middle: something that takes power from the fuse panel and outputs a signal to the speaker. (or maybe takes the audio signal off the speaker and processes it and sends it somewhere else.)
It doesn't make sense for the black plug to ever meet the white socket. -that would be quite loud...and then quite silent!
I hope there isn't live voltage on those two pins flapping in the breeze: that's asking for trouble!
I'd only plug this one in with that black plug insulated and monitored with a voltmeter: maybe figure out what it's up to.
I'd also look in the lamp circuit wiring for a plug/socket pair of the same type.
-------------------- All I ask is a wide screen and a projector to light her by...
Posts: 3523
From: Bristol,RI, USA
Registered: May 2010
posted April 17, 2016 03:36 PM
OK my turn! I think the white that is soldered to the speaker is for an extension speaker.
The black may have been for a remote of some sort. For example, a remote switch to lower the lamp voltage.
Either way the two do NOT belong together. I agree with Steve. I would definitely insulate the prongs. But I would also take a voltage reading to see if it is live.
Posts: 7016
From: Long Island, NY, USA
Registered: Jun 2003
posted April 17, 2016 06:48 PM
The extension speaker idea is a possibility.
The problem with doing this is there is no cutoff of the internal speaker when an external one is plugged in, and the two speakers at the same time could overload the amp.
-doesn't mean nobody'd try it! You see all sorts of unlicensed surgery on these machines!
I bet this machine has the DIN external apeaker jack with speaker cutoff like the STs and GSs do. Maybe the guy had a massive stash of these other jacks and wanted to use them.
-------------------- All I ask is a wide screen and a projector to light her by...
Posts: 720
From: Worthing, West Sussex, UK
Registered: Feb 2009
posted April 18, 2016 04:06 AM
Steve, the DIN socket is still there, and still connected. Obviously a standard DIN connection just didn't cut the mustard for our intrepid hacker!
Posts: 7477
From: Manchester Uk
Registered: Aug 2012
posted April 18, 2016 04:15 AM
As Steve says Stuart, don't plug white to black whatever you do!!
If you plug this projector in, the first thing you need to establish is what voltage is present at the 2pin black plug connector.
I cannot imagine, what the intention of this "flying cable" ever was, given that it comes directly off the transformer and has no fuse protection in circuit from what I can see of it. Whatever it was used for, it needs disconnecting from circuit and then try to ensure the original circuit path remains as was after desoldering.
Presumably the white speaker connector was somebody's attempt to get an external speaker connection or a line level input into something? It's all wrong either way.
-------------------- "C'mon Baggy..Get with the beat"
Posts: 720
From: Worthing, West Sussex, UK
Registered: Feb 2009
posted April 18, 2016 07:39 AM
Therein lies the confusion, Maurice. Perhaps the flying lead was to connect the lamp to another transformer? Anyway, I'm hoping to remove all extraneous cabling at the end of the week as I'm flying abroad for work tomorrow and won't get a chance to look at it.
Posts: 7016
From: Long Island, NY, USA
Registered: Jun 2003
posted April 18, 2016 08:06 AM
The other transformer is often external. If you mind your phasing you can even get away with adding a second transformer in series with the internal one. It can be smaller/cheaper than a single transformer powering the lamp alone.
(If that's the case here the lamp will not light. All the voltage will show up across those two disconnected pins.)
I don't think this machine is beyond rehab: a little judicious unsoldering to get rid of all the Frankenstein stuff may work wonders!
-------------------- All I ask is a wide screen and a projector to light her by...
Posts: 740
From: Hamilton, Ontario, Canada
Registered: Dec 2014
posted April 18, 2016 08:18 AM
I agree with Steve. Just unsolder the rogue cabling, and then try it as per normal. I would swap to a normal bulb as well of course...
I totally have always wanted this little unit and have kept an eye on it on ebay for some time.... I think it is very worth trying to get it going, safely!!! Cool Machine!
Posts: 7016
From: Long Island, NY, USA
Registered: Jun 2003
posted April 18, 2016 08:47 AM
Maybe start with removing that external speaker spigot: I'd say we are unanimous this is good for nothing and removing it won't hurt anything.
(Projector repair by committee!)
The other one may actually be broken into the circuit and require some kind of a jumper in place to bring the lamp back to life. (That voltage measurement and observation of the lamp is a big clue here.)
-------------------- All I ask is a wide screen and a projector to light her by...