This is topic JS-200 series processor problems in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Michael Wohlford (Member # 905) on 11-26-2001, 07:09 PM:
We have 2 screens which have JS-200 series processors, both model #'s JPS-10D. Recently, both have been cutting out during the movie, even during the movie tunes (intermission music). We put the processors in bypass during the rest of the film. The problem goes away until removed from bypass. Our technician has came in and calibrated it with tone film and his equipment. He didn't find anything wrong with it. He adjusted the jax light, checked the wires, etc. I thought it was the amps but found out that if you turn the processor off, then back on, the audio restores, but temporarily. Our amps are peavys. They both started going bad at pretty much the same time. Anyone have or had the same problem? Anyone have any suggestions?
Posted by Joe Ritter (Member # 804) on 11-26-2001, 07:36 PM:
On the JS-200------I happen to have a technician here tonight and he said that he had the same problem. It is the foremat card----bypass switch (pushbutton) needs to be cleaned woth a good contact cleaner. Take the foremat card out and try to get cleaner in the bypass switch. work it a couple of dozen times to get the cleaner in the switch. This will buff up the contacts and clean them and it most likely will play fine. If this doesnt work you will need an new foremat card.------Try it ----Joe Ritter------
Posted by Randy Stankey (Member # 64) on 11-26-2001, 09:36 PM:
When the movie is running, if you look at the noise reduction card on the left hand side of the processor, under the window, do you still see the input meters on the noise reduction module fluctuating/bouncing up and down when the sound dies? If so, then you have likely eliminated everything from there, on back to the projector. If not, then you have to go back through the system and check it. Check your JaxLite, solar cell and preamp box. You can swap JaxLites and Preamp boxes with another projector that you know is good. Do an A-Chain check with test film and an O-Scope to check the cell. From there, check the preamp inside the processor. Swap it out with another house if you think there's a problem there. (Just don't mix them up. You need to put them back in their original houses eventually.)
After you have eliminated all that, you can check the power supply. It's the module all the way on the right.
You'll need to make sure there are two red lights (+15v and -15v) and a green one (Backup voltage).
If one or both of those red lights go out on you at any time you'll lose your processor. If the green light is still on, you can put the processor in BYPASS, like you have been, and it'll run in MONO until you can figure out what's going on. Pressing the BYPASS button disables everything inside the processor except the circuits needed to get the signal off the preamp and the volume control.
If you decice that it is the power supply, take a supply out of another house and put it in there. That'll keep the more important movie running until you can effect repairs. To get the house that you robbed the power supply running, plug in your emergency backup supply that you should have gotten with the processor. It's one of those little black wall transformers. Plug it into the back of the processor and into the wall socket. You can leave the whole power supply out of the unit. As long as that wall transformer stays plugged in you'll be able to run in MONO/BYPASS.
Contact your purchasing agent and get an R/A number for the power supply you took out. (You'll need the serial number off the back of the supply.) USL will send you a new supply. Slap that baby in and put the old one back in the box, fill out the paperwork, stick the address (supplied) on the box and mail it back. You'll get a $$ credit when they receive the old supply.
If it's not your power supply, look at the format card (The one with the volume control.)
If it's not the format card, look at the EQ cards.
The Noise Reduction cards and the matrix cards, etc. (The ones between the preamp card and the format card) are possibilities but, since you say it happens during Non-Sync I tend to think that there aren't any problems there.
My bets are 1) The power supply module and 2) the format module.
Posted by Don Sneed (Member # 955) on 11-27-2001, 07:38 AM:
Michael, I had this problem many times, it's the format card, if only one channel, try this on the Peavey amps...on some models the volume control can be pulled out to defect a or bypass a DDT circuit, if yours does try pulling out & pushing back in several times, this will clean the switch, some models have a push button, do the same, if that still don't fix it, with the amp off, pull out the 1/4" phone plug & reinstall it a couple of times, after a while it will collect dust & not make a good contact to the jack, I also seen these problems on Peavey amps in cinemas...but I would say it it the Format card !!
Posted by Joe Ritter (Member # 804) on 11-27-2001, 09:43 AM:
PS to previous post------I apprecieate the pix your staff put on for me, It is almost accurate. You must be phsycic(sp). The only error is that I now have white hair and an Amish type beard. I will send you a real photo soon but like the one you gave me.-----Thanks---Joe Ritter---
Posted by Gordon McLeod (Member # 33) on 11-28-2001, 12:01 AM:
Also check the bypass relays on each eq board
Some of the older ones were very flacky
Posted by Steve Guttag (Member # 268) on 11-30-2001, 12:45 AM:
And last but not least....check the power supply module...if it has a "standby" button, get rid of it! they are notorious for dropping one of the power rails....during the failure...check to see if both of the power LEDs are lit.SG
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"Old projectionists never die, they just changeover!"
Posted by Pete Naples (Member # 761) on 11-30-2001, 04:35 AM:
I don't have many Ultra Stereo units here, but every single one has suffered the standby switch failure, I just strap 'em out and it never causes a problem again. I noticed that new PSU's don't have the switch at all.
Posted by Ken Layton (Member # 133) on 11-30-2001, 09:57 AM:
Same here---I've had several of the power supply standby switches go bad. I remove them and insert jumper wires in the pc board. End of problem.