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Author Topic: Ultra Stereo sound dropout Frank Dubrois Jedi Master Film Handler Posts: 896 From: Cleveland, OH Registered: Mar 2005 posted 07-20-2006 07:45 PM                    Interesting problem here. Ultrastereo js-200 unit worked find until a few days ago, then the sound from the front became VERY low. The surrounds sound fine. The cards were removed and the contacts cleaned, cards replaced, worked fine again for about 20 mins, then back to very low sound levels up front. Coincidence? I have not had the opportunity to test anything yet, but I was wondering if anyone else had this problem before? Currently it will does not function as it should even when the card contacts were cleaned again. It is running in bypass. [ 07-21-2006, 06:30 PM: Message edited by: Frank Dubrois ]  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 07-20-2006 08:27 PM                     Over the years I've seen literally everything that can go wrong with these units... Most common problem is a failed format module, after that bad output relays... these can just be bypassed if your power amps have a delay on feature. Also, the power supply bypass button should be bypassed since every one of them fails eventually. Are both of the rail LED's lit on the power supply module when it fails or does one or both go out? If so just bypass the power supply button. Newer modules don't have the power backup button. Any of the other modules can also fail....swapping modules between units is the best wway to diagnose which module has failed. Be sure to keep track of which module camne from where and place it back there when you're done! BTW: Gold plated card contacts shouldn't ever need cleaning.... gold does not oxidize and if you do clean it the coating is so thin (measured in microns) that improper cleaning will remove some of it and its plated quality. Use something like Caig Pro Gold or similar to clean gold contacts and above all don't clean them with a pencil eraser . If fingers are bad then replace the card... if sockets(edge connectors) are bad then replace the backplane. Mark  |  IP: Logged Frank Dubrois Jedi Master Film Handler Posts: 896 From: Cleveland, OH Registered: Mar 2005 posted 07-20-2006 09:21 PM                    Unfortunatly we dont have another unit to swap cards with. I didnt spend a lot of time with it, and its all new stuff to me, so I didnt want to go poking around until I at least had a manual. The amp in the rack is a QSC 1400..and I didnt get a good look at it either. The surrounds in the auditorium sound fine, just the front speakers are very low. Unless your standing upfront, you cant hear anything. I'm hoping its something we can bypas or adjust, as of now, its playing in bypass mode.  |  IP: Logged James Westbrook Phenomenal Film Handler Posts: 1133 From: Lubbock, Texas, Usa Registered: Mar 2006 posted 07-20-2006 10:15 PM                     Frank, Is this auditorium running 2 channel stereo (center channel and surround) or 4 channel? If it's 4 channel, you could swap out a right eq card with the center and see if the volume in the front remains stable. (or the left eq card with the center).  |  IP: Logged Frank Dubrois Jedi Master Film Handler Posts: 896 From: Cleveland, OH Registered: Mar 2005 posted 07-20-2006 10:29 PM                    I beleive its 2 channel. Since i'm completely unfamiliar with it, I remember it had the preamp card, NR card, two other cards, then the power supply. We have no spare cards to swap unfortunately. I notice there isnt a manual for this unit. Does anyone know if one of the manuals listed is pretty close? The JS-200 looks pretty similar. In reading the troubleshooting area, it says if the front speakers work in bypass, but not in normal play, theres a problem with the unit. The WHOLE unit? I would a think a card might be bad, but the whole unit?  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 07-20-2006 11:28 PM                     Jumper the output relay in the center chan eq card... that may very well fix it, especially if its an old blue relay. I've had a number of failures of the later Aleph type relay too. A very common problem . Also, yank the format card out(with the power off) and look at the pins of the bypass switch... if they are gold the bypass switch is probably ok but if the pins are solver color then that switch also needs to be replaced. If you have sound from the center in bypass mode then the power amp is not at fault. Mark  |  IP: Logged Frank Dubrois Jedi Master Film Handler Posts: 896 From: Cleveland, OH Registered: Mar 2005 posted 07-20-2006 11:37 PM                    Since I really didnt take a close look at it, and have never worked with this stuff before...what do you mean jumper the output relay?  |  IP: Logged Darryl Spicer Film God Posts: 3250 From: Lexington, KY, USA Registered: Dec 2000 posted 07-21-2006 10:53 AM                    are you getting any sound from the front. Does it sound muffled. Turn off the surrounds and verify that the front has sound. There may be an issue with your center speaker's high frequency horn or crossover for that speaker. Note on your monitor if you have the ability to listen to each channel and in processor and amp mode on the monitor check the sound for clarity.  |  IP: Logged Frank Dubrois Jedi Master Film Handler Posts: 896 From: Cleveland, OH Registered: Mar 2005 posted 07-21-2006 11:18 AM                    there is light sound from the front, but the surrounds drown it out almost completely unless your standing up front. In bypass, the front works.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 07-21-2006 12:53 PM                     I would recdomend having a service engineer come in and deal with it If you are not familiar with soldering technique I would not attempt it I use a cleaning rubber from MG chemicals to remove build up on gold plated contacts as they may not oxidise but they do get enviromental dirt on them that can make them flaky http://www.mgchemicals.com/products/802h.html  |  IP: Logged Clint Koch Phenomenal Film Handler Posts: 1435 From: San Luis Obispo, CA, USA Registered: Feb 2002 posted 07-21-2006 06:21 PM                     Hello all, I spoke with Frank and had him try some things at the site today. What we came up with is the Standby switch on the power supply was causing the problem. When he pushed the switch on and off a bunch of time the center channel came back on. A servive repair power supply (without the Standby switch) is on it's way for Saturday delivery. Thank you all for your comments as they were all right on. Clint  |  IP: Logged System Notices Forum Watchdog / Soup Nazi Posts: 215 Registered: Apr 2004 posted 06-24-2011 05:58 PM                 It has been 1798 days since the last post.  |  IP: Logged James Ness Film Handler Posts: 47 From: Houston, TX, USA Registered: Jan 2008 posted 06-24-2011 05:58 PM                        having this exact same problem right now tried messing with the bypass button to no avail, tried taking the format card from another processor, no change. hitting the bypass button works as normal, everything comes through the center and you can hear the dialogue clearly but as soon as you go back out of bypass it goes away again all channels are fine except the center, its quiet and kinda muffled. was going to try the standby button but it appears as though mine don't have a standby button any help would be appreciated, thanks  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 06-25-2011 09:22 AM                     Power down the processor.... Pull the format card (the one with the fader control). Look at the contacts sticking up through the bypass switch. If they are not gold plated then the bypass switch is most likely bad. If you have gold plated contacts then you are probably ok and the problem lies some where else. If you have another processor on another screen then substitute modules from it one at a time until you solve the problem. Be sure not to get the modules mixed up! Mark  |  IP: Logged

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