Film-Tech Forum ARCHIVE: Loud static in booth monitor

This is topic Loud static in booth monitor in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Jim Ziegler (Member # 86) on 01-22-2005, 12:38 AM:

One of our MS-100 monitors emits very loud static, regardless of the volume setting. When we turn it up, we can also hear the signal from the amps, but, the only way to make the static stop is to turn it off. Does anyone have any idea what may be causing this? The static is also present in a set of headphones when we plug them into the headphone jack.

Posted by Aaron Sisemore (Member # 145) on 01-22-2005, 12:56 AM:

Easy (but unorthodox) fix:

Give the monitor a hard smack- the noise should change or disappear entirely.

There is likely something loose or corroded internally causing the static, I have had the same thing happen to MS100 monitors and giving them a good smack seemed to cure it. [Big Grin]

-Aaron

Posted by Dominic Espinosa (Member # 2122) on 01-22-2005, 03:48 AM:

quote: Aaron Sisemore
giving them a good smack seemed to cure it.

Man am I glad he doesn't take that approach with the projection staff...

Just for curriosity sake...Would it be likely something loose on the input or in the monitors volume control or something else entirely?

Posted by Jim Ziegler (Member # 86) on 01-22-2005, 04:50 AM:

I took the top off and re-seated all the connections and still nothing.. I will check them all again tomorrow. All of them were not fully seated, which I found odd...

Posted by Christian Volpi (Member # 2370) on 01-22-2005, 08:28 AM:

quote: Aaron Sisemore
Give the monitor a hard smack

Glad to hear I'm not the only one that did this. I used to have an ultra stereo monitor that I must have smacked a thousand times. Heck, it worked.

Posted by John Walsh (Member # 168) on 01-22-2005, 12:49 PM:

This is a problem with older Component Eng MS-100's. The 20 pin (or so) connector to the amplifier module gets tarnished, resulting in a poor connection. The company knows about it. When I mentioned it to them (about two years ago) the fellow I talked to sent me a new module at no charge, but you must return the old one.

Posted by Jim Ziegler (Member # 86) on 01-22-2005, 01:47 PM:

Can these contacts be cleaned?

Posted by Mark Gulbrandsen (Member # 72) on 01-22-2005, 02:02 PM:

If you do clean them use Caig Laboratories De-Oxide or Pro Gold contact cleaners. A tiny bit of that stuff on them and they will probably never give trouble again. This is as good as contact cleaners get!
Caig Labs Web Site

Mark

Posted by Jim Ziegler (Member # 86) on 01-22-2005, 05:00 PM:

The best contact cleaner I could find here in Selma was Radio Shack. However, that did the trick! Thanks for all the help! I will check out that other brand and try to get some in here for the next time I have an issue.

Posted by Paul Vollmers (Member # 927) on 01-22-2005, 05:20 PM:

I used some Radio Shack spray contact cleaner on a volume knob rotated it several times and bingo ..........no more static.
Give it a try.

Posted by Chris Boland (Member # 3549) on 01-06-2006, 12:44 AM:

quote: John Walsh
This is a problem with older Component Eng MS-100's. The 20 pin (or so) connector to the amplifier module gets tarnished, resulting in a poor connection. The company knows about it. When I mentioned it to them (about two years ago) the fellow I talked to sent me a new module at no charge, but you must return the old one.

As this is my first post, I should say I don't mean to bring back old threads, but I also didn't want to start a new one.

At the theatre I work in we have several MS-100s with this problem. The last time we had a technician in from Toronto that knew how to fix it (I believe it was Rick Long) was almost 2 years ago.

My question. The connector board to the amplifier, is this the panel located on the back of the unit where the various channels from the Processor/Power Amps are connected? Or is there a terminal block inside the unit that is cleaned?

Posted by Dominic Espinosa (Member # 2122) on 01-06-2006, 04:09 AM:

quote: Chris Boland
As this is my first post, I should say I don't mean to bring back old threads, but I also didn't want to start a new one.

Fear not for bring an old thread up is encouraged as opposed to having extra threads about the same topic.

Oh and welcome to Film-Tech!
Sweet...I got to welcome somebody...

Anyhow, back to the topic. I'm pretty sure it's the connector on the rear of the unit.
I'm sure someone will be along shortly to correct me if I'm wrong though [Wink]

G'luck.

Posted by John Walsh (Member # 168) on 01-06-2006, 12:00 PM:

The connector for the amplifier module is inside. You'll have to actualy remove the MS100 to get at it.

That rear PC board where the audio connectors go can usually be removed and unplugged, (there are two plugs on the back) saving the time of disconnecting all audio leads. However, on some units, they used ty-raps to hold wires out of the way, and sometimes those ty-raps were pulled a little too tight to allow you to get the board out far enough to unplug it.

Posted by Chris Boland (Member # 3549) on 01-06-2006, 02:15 PM:

Thanks for the welcome Dominic!

John, is it relatively easy to get at the connector? Just wondering if this is a 20 minute or a 2 hour job. [Smile]

Thanks!

Posted by Brian Long (Member # 2964) on 01-06-2006, 03:36 PM:

There was an issue with a batch of MS-100's where the connector that the STK4024/6 power amp module plugged into was changed. The pins on the amp module didn't seat into the connector as far as they needed to. This connection is what causes the static. Unfortunately, the static problem didn't show up until the units had been in operation for a while.

We have remedied the problem but, in the mean time, fixing the units that are in the field has been ongoing. The fix can either be done in the booth or you can send the main board with amp module in for us to fix.

The fix entails removing the top cover and then the main board. The 15 pin surface mounted connector that the amp module plugs into needs to be de-soldered and replaced with a new one.

Please call our office or e-mail me so we can either send out a new connector or make arrangements for you to send the board in for us to fix.

Brian Long

Posted by John Walsh (Member # 168) on 01-06-2006, 03:46 PM:

Once you have the MS100 out of the rack, it's an easy 5 minute job. There's plenty of room inside to work. It's getting the MS100 out, then back in the rack that could be the 2 hour job, depending on how buried the thing is in there, and many ty-raps the installer used!

Posted by Rick Long Jr (Member # 541) on 01-06-2006, 05:54 PM:

Chris, I recommend before you tackle this yourself, you give me a call. You don't have to disconnect everything on the back. Norm has our office number. I should be there Monday the 9th.

Posted by Chris Boland (Member # 3549) on 01-06-2006, 11:17 PM:

Rick, sounds good. I will definitly try to give you a call sometime Monday.