Conference 7.286::atarist

I had a similar problem and I thought my monitor was dying when I first saw
it. Turns out the problem was caused by having the monitor sitting on top of
the hard drive I had just finish building. I assume it was caused by
interference from the switching power supply in the hard drive.

I couldn't tell you how to fix it except for to move the sound module. Moving
the hard drive off to the side a little helped in my case and getting two feet
away cured the problem. You could try moving the module below the ST if that
is more doable then moving it horizontally.

	Ray

	re .0

	If the problem is from power feed back, you could try:

		1) making sure all your stuff is well grounded.
		2) Put the Monitor and the Midi stuff on different circuits

	If the problem is from interfence, then try:
		1) Put some aluminium foil between the two.
		2) Move the cables from them so they(the cables) are as far
		   apart as possible.


	Jim Patterson

    
    	It is probably radiated fields coupling into the monitor...
    Placing a shield of metal (grounded) may very well help... or if
    it coupling in on the cables, try some of the Rat Shack clamp-on
    RF chokes...
    
    	It wont cause any reliability problems to the monitor however,
    if that is a concern...
    
    	/john

    Is there a fan in it ?? If there is then that is your problem, however
    it could also be the transformer. There isn't really any easy fix
    other than moveing the devices away from the monitor.
    
    Peter

    
    I faced similar problems. Reversing the polarity of the power plug
    did it (don't ask me why).
    
    Bernd
    

My monitor image bounces around whenever the iron thermostat kicks in,
when the iron is on the same circuit.

It also will wiggle if you place any live transformer too close to it. 
The magnetic field of the transformer will interfere with the path of
the electrons.

Problem solved.  I swapped the Kurzweil with another module and no more problem.

Thanks

Chad

I thing the Kurzweil is only Class B, whatever that means.

"only class B" means that it conforms to the most stringent level of
radio frequency emissions limits established by the Fedral
Communications Commission in the U.S.  I think only Germany's VDE has 
more stringent limits than FCC class B, but I'm not sure of even that.

These are high frequency limits.  Chad's problem is a low frequency
60hz thing.

>Communications Commission in the U.S.  I think only Germany's VDE has 
>more stringent limits than FCC class B, but I'm not sure of even that.

What is "Germany's VDE" (what does VDE stand for -- German words are fine)


thanks

Chad

Look on the bottom of your DEC keyboard - just under the FCC ID number
is the words "Funkentstvrt nach allgemeiner Genehmigung 529/1970 (VDE
0871 Klasse B).  Loosely speaking, VDE is German for "FCC":-).

Yeah, but what does it mean (I mean in German)?

Here is go just matching words to letters, not based on any knowledge

VDE

Verein Deutscher Elektrotechniker = (would be if this were to exist)
Organization of German Elctrical Engineers

Chad

            

    
    
    definitely correct!
    
    VDE = Verein deutscher Elektrotechniker  (Technicians)
    VDI = Verein deutscher Ingenieure        (Engineers)
    
    where VDE makes the rules for working with electro/electronic stuff,
    and VDI is a community of engineers of all resorts.
    
    Bernd
    

	re. -1

	And, to think, I always assumed VDI was Vertical Display Interupt.

	Oh, well.

	Jim

    
    Now I have a problem with my monitor. In a former reply I suggested to
    turn the power connector, this doesn't help anymore.
    Since a few days I have a ripple and flimmer on my original Atari
    monitor. Nothing changed in the configuration at that day, no equipment
    with magnetic fields in the near. I tested the shielding of the cable,
    I took the monitor apart and looked for the shielding there, everything
    ok. In former days I had this symptom as soon as the washing machine
    started to heat, now it's all the time. The strange thing about is that
    the problem occured from one day to another without changing or adding
    equipment. The monitor works ok on my brother-in-law's Atari. My color
    monitor also works without any problems. Could it be that this is
    caused by the weak 1040' power supply which has to feed 4MB memory and
    two internal 3.5 drives? (I have the computer in a tower box far away
    from monitor and keyboard). Any hints where to check?
    
    Bernd
    

    
    To answer my own quAt home I did a bit more testing and by tand
    accidentely I disconnected the color monitor from the Atari (I have both 
    monitors connected simultaniously, they are switched by the monochrom
    detect line internally with a switch) and the flimmer went away. Now
    I inspected the cable and found out that the shielding was connected
    to ground on both sides of the cable. Di the shielding on
    the monitor's side of the cable did the fix! I only can't understand
    why this problem occured so instantly. The cable was that way since
    months.
    
    Bernd
     

If I have my color monitor powered on when I am using the monochrome monitor,
then the monochrome monitor's display gets the shakes.  As long as the color
monoitor is turned off the monochrome display is fine.

	Ray

    
    first, sorry for the typos in my last reply. I had a bad modem 
    connection.
    re. -1
    the flimmer occured both with power on and power off at the color
    monitor. Just removing the connector removed the shakey screen.
    I disconnected the shielding from ground at the monitor side and
    the display got way better.
    
    Bernd
    
    

You might have a ground fault somewhere in your electrical wiring.  You can
pick up outlet checkers pretty cheap at Radio Shack that have a set of LEDs
on them to tell whether or not there are problems with the household wiring.

Did you happen to change what wall plugs things were plugged into recently?

							-Dave

    
    that might be the problem. I'm living in an relatively old house
    where they didn't have a three-wire power line with external ground
    at that time. 
    The only things added lately to the power outlet were a desktop clock
    and the modem.
    In the way the monitor looks now (with the disconnected shielding on
    the color monitor's side) I can live with. It's far better now.
    Thanks for all the suggestions! Anyway I'll try to get those testers.
    
    Bernd
                                                                         

    
    I'm facing a strange problem with my computer these days. All started
    when I extended the cable lenght of my mono monitor. In the first run
    I had a solid picture as long as the background was white, like in a
    complete open window. So every black and white parts were ok, only the
    desktop with it's dark or grey parts had alternating dark and light 
    vertical stripes, each about 2-3 cm in width. During examination of
    the symptom the screen suddenly went completely dark. A bit scared
    about the life of the GLUE (which is SMD and I can't replace on my own)
    I shut off and put that original monitor cable back.
    Then I tried a reboot. Desktop came up with no icons at all.
    I disconnected the DMA connector and rebooted. After a while I had that
    message on the screen that the computer couldn't access drive A with
    the choice to Ignore, Abort or Retry. GEM was not started by now.
    Next I swapped the floppy in drive A and did another boot. This time
    the computer came up just fine with the two floppy icons and the
    trashcan. I checked out the floppy which was previously in the drive
    and couldn't access it because the bootsector was somehow damaged (the
    floppy certainly worked ok before).
    Now I wanted to check out some software to insure that everything is
    ok, except that I still had no HD access (no icons as soon as the
    computer is booted with connected DMA, no matter if the HD is powered
    on or off). After a while the information on my screen went away. I
    still had a light rectangle in the middle of my monitor with sharp
    edges to the black borders, but in that window everything went crazy.
    You could imagine that something at the top of that window looked like
    a menu-bar, but it looked like it would move very rapidly in horizontal
    direction behind kind of "fog". First I thougth the Sync information
    from the GLUE passed out, but in that case I believe I had no stable
    window in the middle of the screen of which just the contens seem to
    go crazy. 
    So this is the status of my computer in the moment. Btw if I happen to 
    boot that thing ok from floppy and have to reset for any given reason,
    after the reset the screen always looks like described above.
    
    Any ideas besides swapping the GLUE? (next time I buy a computer I let
    the dealer open up that thing and show me that not a single SMD chip is
    on the board!!! I really don't know why Atari did this, lots of space
    on that motherboard.)
    
    Bernd
    
    
    

Try the video shifter - it's socketed in all system I have seen, a
40-pin DIP inside a separate RF cage.

This could also be RAM.

    
    Yup, the Video Shifter was the problem. Not completely down, but 
    somehow "weak".
    Takes a load off me (still getting goose bumps when thinking of the
    @#$%-GLUE) ;-)
    
    Thanks,
    Bernd
    

Okay, now replace the DMA controller chip, another Atari-specific
40-pin socketed chip, and you should be all set.

(I'm starting to think I've fixed too many of these.)

    
    Now, it looks like it was not a problem of the DMA controller chip, but
    of the operating system I installed last week.
    The situation was that I had no working HD at that time because I still
    needed some GALs for the SCSI host adapter. The adapter and the HD was
    connected, but without power when I had that said symptom. So I got
    no icons when booting the system with the adapter connected, but
    everything was ok with a disconnected DMA cable.
    During Easter I connected the drive of a friend and could boot up just
    fine from disk, so the DMA chip obviously is ok. But when I tried to
    boot from floppy with a shut-off HD and the DMA cable connected, just
    the same thing happened. As soon as I disconnected the cable and
    rebooted, everything was ok again.
    So it seems that with the version of KAOS I have, published in a mag 
    last year and programmed into EPROMs, it is not possible to boot up the
    system with a connected powerless HD, nor is it possible to switch the
    HD on after bootup and run AHDI to make it known to the system.
    
    Thanks anyway for the hint, Jeff, but I rather like this solution than
    to solder out a 40-pin chip and put another new one in. 
    
    Bernd
    

A powered off device on the DMA port may  present an unreasonable load
to the DMA controller or to the other devices on the DMA data bus, such
as the floppy controller.  It is generally a bad idea to try to run with
powered-off devices on the DMA port.

re:      <<< Note 798.26 by PRNSYS::LOMICKAJ "Jeffrey A. Lomicka" >>>

> as the floppy controller.  It is generally a bad idea to try to run with
> powered-off devices on the DMA port.

DONT'T DO IT. I learned it the hard way: while my powered-off hard disk
stayed connected, I had a program running which wrote to the diskette.
Only one night long. Program worked fine. BUT when I tried to read the
data from diskette, that file contained junk, the directory contained
junk, and most of the other files contained junk. It took me a lot of
work to restaurate (most) of 4 weeks of temperature data. Now I disconnect
the hard disk when I use the ST with floppy alone.

    
    Good to know! And I was wondering why I couldn't even format that
    floppy after I had those troubles last week. I had to trow it away!
    This was the first time ever I had a powered off device on the DMA
    port because of those three missing chips in the adapter, and I didn't
    wanted to disconnect all the cables in the tower case (due to space
    problems they're hard to access). Now I know that I should spend a
    little more work to protect my hardware during upgrades/changes.
    I think this is a good hint in this place for other users also, I
    learned my lesson! (I was close to a heart failure :-) )
    
    Thanks again,
    Bernd