🚀 go-pugleaf

On 21 Dec 1996 09:27:52 +1100, cdewick@lios.apana.org.au (Craig
Dewick) wrote:

>In <ueengm4r25.fsf@auda.mlfarm.com> ron@mlfarm.com (Ronald Florence) writes:
>
>>One of our monitors, a Sun/Sony 16-inch color multiscan, model
>>365-1130, occasionally arcs while in use.  It has happened twice, at
>>about a one week interval: a snapping sound, an apparent flash on the
>>screen, the display goes black for an instant, then is fine.
>
>>Is there a cure we can apply for the arcing?  I hate paying the
>>freight to ship these monsters around.  Thanks,
>
>Sounds like now is a good time to get your monitor looked over by a service
>agent. 
>
>Those flashes are most likely stray arcs of EHT, and some possible reasons
>could be that the EHT is taking a different path other than through the
>anode of the tube in your monitor is that either the inside of the monitor
>is very dirty and providing a shorter conductive path to ground some of the
>time, and/or there's an intermittent fault which is causing the anode
>connection to break somewhere. There are probably a few other likely causes
>as well.
>
>If you don't want to send the monitor away, and you know someone who is
>experienced in monitor or TV servicing, ask them to have a look. They'll
>probably look at all the components in the EHT section, check for problems
>with the mounting, soldering, etc. of these components, and check the
>connection from the output of the EHT transformer to the anode of the tube
>is not becoming intermittently faulty. 
>
>What other symptoms are there? Does the arcing occur randomly, or a certain
>time after switch-on? Has the inside of the monitor ever been cleaned out?
>Depending on the environment, if it's dusty and more than a little humid
>this might be a contributing factor. 
>
>Regards,
>
>Craig.
>-- 
>            Craig Dewick. Send email to 'cdewick@lios.apana.org.au'
>   Point a web browser at 'http://lios.apana.org.au/~cdewick/sun_ark.html' to
>       access my collection of Sun information and links to other places.

One possible problem is that your dag ground { the wire strapped to
the body of the picture tube. is loose or is not properly connected to
the DAG return. {usually on the Neck board, sometimes to  the
chassis}. If you also have a shield around the picture tube, voltage
at the dag will charge until it reachs a potential to arc to the
picture tube shield, ever few second, or minutes.

The other possibility is an insulation failure in the high voltage
area or possibly at the focus control.
Andy J. Insalaco
ajilight@csra.net
Augusta, GA 
Home of the 96 Olympic Golf - Oops, My Bad :)