[comp.sys.amiga.hardware] Sleeping 1084 monitor

labc-1id@web-1c.berkeley.edu (Joe Chung) (03/10/91)

HELP!

About a month ago, my 1084 monitor, which I've had for over 4 years, started
to go to sleep.  I had to hit it on it's right side to get it to wake up.

I knew about the problems it has with it's power supply.  So I took it apart
and examined the power supply.  I found a pin around the transformer that
wasn't soldered very well, so I proceeded to resolder it.  But my montior
continued to go to sleep.  So I took the power supply out again and reflowed
all the solders around a few large caps.

After that, it worked for a day and a half and the monitor went to sleep
again!! So now I must assume that some part is faulty.  Something that
likely sinks a lot of current and goes out after it gets hot.

Can anyone help me out on this?

Thanks
-jc
--
labc-1id@web.berkeley.edu
No news is good news.

paulz@hpspdra.HP.COM (Paul Zander) (03/12/91)

Intermittent hardware problems can be very difficult to find in any
piece of electronics equipment.  Sometimes the part is sensitive to 
temperature.  Open the case and turn on the equipment.  KEEP YOUR HANDS
AND OTHER BODY PARTS CLEAR OF THE HIGH VOLTAGE.  Use a small hair dryer
to try heating different parts.  Be careful not to melt them.

Before there were holes in the ozone layer, technicians often had a
special bottle of freon to chill suspect parts.  You might contact a
real dealer in electronics (not Radio Shack) to see if there is an
environmentally "safe" version of "Koolz it".  

lou@vaxsc (03/13/91)

In Message <1991Mar9.215854.12214@agate.berkeley.edu>, Joe Chung writes:

>HELP!
>
>About a month ago, my 1084 monitor, which I've had for over 4 years, started
>to go to sleep.  I had to hit it on it's right side to get it to wake up.

If this is the monitor that is OEM'd by Magnavox I have a suggestion for you.
Unfortunately it's not a great one, perhaps someone can help me find parts 
for mine as well.  The monitor likely has a bad flyback transformer.  What
happens (in some Magnavox monitors) is that the 2nd anode lead coming out of
the transformer (literally) burns up, and the carbon increases the resistance
of the contact (within the xfomer).  Hitting on the side causes the lead to 
shift or otherwise move slightly enough to find a place where it can once again
make contact.  And yes, once it heats up, the contacts degrade.

So my suggestion is to get the flyback transformer replaced.  Unfortunately,
I haven't been able to locate one for mine, and Magnavox won't sell me one
so I have to take it to a repair center.  (Which I havent yet done).

I could be wrong on this, so don't take it as gospel.  Let a repair center
be the final word, not mine!

If some one knows of a better way, please let me know.  Mine is essentially
the same monitor as the Commodore 2002 (?), also OEM'd by Magnavox.

Hope this helps!

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