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Author Topic: GS-1200 Lamp Replacement
Bob Pucci
Jedi Master Film Handler

Posts: 520
From: Westerly,RI
Registered: Jun 2003


 - posted August 01, 2003 09:17 PM      Profile for Bob Pucci   Email Bob Pucci   Send New Private Message       Edit/Delete Post 
Can a EJL lamp be used in place of a ESC lamp for the GS-1200?They both have the same voltage and wattage.I replaced mine and now the lamp comes on as soon as you turn on the power.Thanks

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Trevor Adams
Jedi Master Film Handler

Posts: 763
From: Auckland,New Zealand
Registered: Jun 2003


 - posted August 01, 2003 11:37 PM      Profile for Trevor Adams   Author's Homepage   Email Trevor Adams   Send New Private Message       Edit/Delete Post 
Yep. I use 250w/24v lamps-brighter.Trev

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Trevor

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Bob Pucci
Jedi Master Film Handler

Posts: 520
From: Westerly,RI
Registered: Jun 2003


 - posted August 02, 2003 06:43 AM      Profile for Bob Pucci   Email Bob Pucci   Send New Private Message       Edit/Delete Post 
Thanks Trevor

But what I mean is that when I turn on the main power switch the lamp comes on with full brightness like you are projecting a film.I thought it was just pre-heated.I thought that the two bulbs are constructed different inside.I know the ESC cost $7.00 more.Should I try a ESC.

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Mal Brake
Jedi Master Film Handler

Posts: 591
From: Neath, South Wales, UK
Registered: Jun 2003


 - posted August 02, 2003 07:25 AM      Profile for Mal Brake   Email Mal Brake   Send New Private Message       Edit/Delete Post 
Hello Bob. It would appear you have a problem with the GS not the lamp. I have been using these lamps for a number of years without trouble. You need to check the voltage on the lampholder (with bulb removed).If it reads 24v you have a problem.
The ESC is more expensive because the beam is concentrated to fill the 8mm gate aperature. The other lamps are intended for 16mm use so they cover a wider area. Good luck, Mal

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I'm gonna live forever or die trying

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Bob Pucci
Jedi Master Film Handler

Posts: 520
From: Westerly,RI
Registered: Jun 2003


 - posted August 02, 2003 11:11 AM      Profile for Bob Pucci   Email Bob Pucci   Send New Private Message       Edit/Delete Post 
Thanks Mal

I did what you said and there is 22 volts there with the bulb out.I think with the pre-heat there should only be about 3 or 4 volts.Is there anything I can possibly do or look for if I take the back cover off?

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Mal Brake
Jedi Master Film Handler

Posts: 591
From: Neath, South Wales, UK
Registered: Jun 2003


 - posted August 02, 2003 11:35 AM      Profile for Mal Brake   Email Mal Brake   Send New Private Message       Edit/Delete Post 
Bob, I wish I could be more help to you but I have only had a GS for a couple of years so I am not overly familiar with it.(I've used st1200HD's for 25years).I would hate to suggest something that could damage your machine so hopefully there are others on the forum with more experience of the GS. In the meantime I will contact a friend of mine who has the full service manual for the GS and we will look at the circuit.(I am a retired electrician; my friend worked in electronics, so we will have a go!)

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I'm gonna live forever or die trying

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Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003


 - posted August 03, 2003 03:47 AM      Profile for Kevin Faulkner         Edit/Delete Post 
Hi Bob,
You have to be carefull about using the ELC in some of the earlier GS1200's. The extra current drain can lead to problems with the mains transformer. The thing to do is check the lamp voltage with an ESC or EJL lamp and then do the same with the ELC. If there is a voltage drop with the ELC then DONT use it as you could eventually burn out the transformer.
The voltage you have measured is what you would expect from the GS in the first switch position.
As this is happening when the machine is first switched on and just in pre-heat it would suggest possibly a problem with the lamp relay and not the actual switch. It may be stuck. The relay is under the mains transformer next to the fan motor. Try giving it a few taps with the machine switched on to see if cures it. If not then you will have to check the voltages at the mains transformer in case that has developed shorted truns. Does the switch have any effect on the brightness of the lamp while in the pre-heat state? If yes then I would say that the machine has a logic problem and is telling the relay that it is in projection mode. That would most likely be an IC or transistor problem.
Hope that all helps, Kevin.

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GS1200 Xenon with Elmo 1.0...great combo along with a 16-CL Xenon for that super bright white light.

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Bob Pucci
Jedi Master Film Handler

Posts: 520
From: Westerly,RI
Registered: Jun 2003


 - posted August 03, 2003 08:52 AM      Profile for Bob Pucci   Email Bob Pucci   Send New Private Message       Edit/Delete Post 
Thanks Kevin for trying to help me out.I did what you said by tapping on the relay but no luck.Maybe I didn't tap hard enough.There is no difference in the brightness when you move the switch from the pre-heat to the first position.There is a difference from the first position to the second position.I wouldn't know where to check the voltages on the transformer becuse I have no schematic.If the transformer has a shorted turn in the lamp circut would it be ok to use the projector that way?I think that those transformers would be hard to come by.Other than that,the projector works fine.Let me know what you think.Thanks again.Bob

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Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003


 - posted August 03, 2003 06:14 PM      Profile for Kevin Faulkner         Edit/Delete Post 
Hi Bob,
I will have a look at the circuit diagram and see if I can sus out what is going on. It does sound a bit like a logic or switch problem.
I'll get back to you on this, Kevin.

--------------------
GS1200 Xenon with Elmo 1.0...great combo along with a 16-CL Xenon for that super bright white light.

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Bob Pucci
Jedi Master Film Handler

Posts: 520
From: Westerly,RI
Registered: Jun 2003


 - posted August 19, 2003 06:23 AM      Profile for Bob Pucci   Email Bob Pucci   Send New Private Message       Edit/Delete Post 
Thanks to all that tried to help.The problem is now fixed.I took it to a friend of mine and all it was a pinched wire behind the lamp brightness switch.He said that when the projector was made some how the cable got pinched and it finally broke though and the wire grounded out.Thanks again.

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Mal Brake
Jedi Master Film Handler

Posts: 591
From: Neath, South Wales, UK
Registered: Jun 2003


 - posted August 19, 2003 01:06 PM      Profile for Mal Brake   Email Mal Brake   Send New Private Message       Edit/Delete Post 
Hi Bob, I'm pleased you were able to solve the problem.
Mal

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I'm gonna live forever or die trying

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