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Author Topic: Sub-woofer not working
Ian Bailey
Master Film Handler

Posts: 317
From: Nambucca Heads, Australia
Registered: Jun 2003


 - posted 11-10-2006 07:14 PM      Profile for Ian Bailey   Email Ian Bailey   Send New Private Message       Edit/Delete Post 
Hi
While servicing this gear we realised that we had no Sub woofer activity.
Tested cabling from the output of the processor to the i/p of the amp and the o/p of the amp to the speaker-which tested fine.Swapped amps....same problem.
Processor is an early model Ultra-Stereo JS 105/195.
I swapped the Format card with an earlier type Format card(which was all I had to use) still no Sub.I'm not 100% sure if the earlier model Format card(out of a JS 5/95)is compatible with the 105/195.
Cheers Ian

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Dominic Espinosa
Phenomenal Film Handler

Posts: 1172
From: Boulder Creek, CA.
Registered: Jan 2004


 - posted 11-11-2006 03:35 AM      Profile for Dominic Espinosa   Email Dominic Espinosa   Send New Private Message       Edit/Delete Post 
Assuming you're in analog could it be a failure of the SR card?

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Ian Bailey
Master Film Handler

Posts: 317
From: Nambucca Heads, Australia
Registered: Jun 2003


 - posted 11-11-2006 05:23 AM      Profile for Ian Bailey   Email Ian Bailey   Send New Private Message       Edit/Delete Post 
Domonique that is right it is analogue.I just assumed the problem would be the Format card.I'll try swapping the other cards,but they are from an older model.
Cheers Ian

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Gordon McLeod
Film God

Posts: 9532
From: Toronto Ontario Canada
Registered: Jun 99


 - posted 11-11-2006 01:40 PM      Profile for Gordon McLeod   Email Gordon McLeod   Send New Private Message       Edit/Delete Post 
I can't see how it could be the SR card since the USL original design sent a sum of the three stage outputs to the sub (handy for old mag films) If the unit has been upgraded to Digital check that a sub is present with digital
If you have the DTS switch relay in the sub line make sure it is wired correctly
If one inserts the Pink noise generator and you could see if there is noise on the sub output point

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Dominic Espinosa
Phenomenal Film Handler

Posts: 1172
From: Boulder Creek, CA.
Registered: Jan 2004


 - posted 11-13-2006 02:33 AM      Profile for Dominic Espinosa   Email Dominic Espinosa   Send New Private Message       Edit/Delete Post 
Ah, Gordon.
I was under the impression the sub was contrived from the surrounds. My apologies.

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Robert Throop
Master Film Handler

Posts: 412
From: Vernon, NY USA
Registered: Jun 99


 - posted 11-13-2006 09:23 AM      Profile for Robert Throop   Email Robert Throop   Send New Private Message       Edit/Delete Post 
Are you sure that the voice coil isn't open?
Bob

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Clint Koch
Phenomenal Film Handler

Posts: 1435
From: San Luis Obispo, CA, USA
Registered: Feb 2002


 - posted 11-13-2006 11:59 AM      Profile for Clint Koch   Email Clint Koch   Send New Private Message       Edit/Delete Post 
Hello all,

Ian, the older JFM-05 is not really compatible with the newer JFM-10's and JFM-20's. The JFM-05 is a single card edge connection while the JFM-10 and JFM-20 are dual card edge.

On the JFM-10 that you have there is a relay for the sub channel that may be intermittent. I can send you the schematic if you like.

Clint

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Ian Bailey
Master Film Handler

Posts: 317
From: Nambucca Heads, Australia
Registered: Jun 2003


 - posted 11-14-2006 09:51 PM      Profile for Ian Bailey   Email Ian Bailey   Send New Private Message       Edit/Delete Post 
Hi
Ok guys I've gotta admit I stuffed up!!
During the service of this gear I exchanged the power amps so had to replace the input plug to the Sub power amp.This was the first thing I checked when I realised I had no Sub BUT.....I just checked the continuity of the cable with a metre and I had reversed the wires when soldering onto the plug........it was 4:30 am so I can understand how my brain was working!!
Clint thanks for that information now I know what i can keep as spares out of the old 5/95.I would appreciate getting the schematic on the JFM-10 as we are a bit isolated(too many Dollars away from the nearest service tech!!)and any extra information we have helps heaps.
Cheers Ian

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