monitor tech prob

[Paul]

[ukvac] monitor tech prob
hi all

ive got a 19" monitor (orion tube, hantarex chassis)
as an example ive got a jamma 1943 on it and the colour of the sea is purply pink, but when i take the monitor out and rotate it slightly its perfect.

ive checked the connections and all seems well
its the same everytime, normal position its bad, start turning it and it goes perfect
where do i start looking?

any help much appreciated
thanks
paul

 

[guddler]

RE: [ukvac] monitor tech prob
Chances are you don't Paul.

I have the same problem, but the other way wound. By 'normal' I assume
you mean vertical (1943 is vertical isn't it?). Mine does the opposite,
the screen is perfect vertically, as soon as I rotate it horizontally I
get the problems you're describing.

AFAIK, some tubes are fine in one orientation, some in the other and
sometimes they are good for rotating....

If anyone knows how to adjust this out properly using the purity ring on
the yoke (I'm assuming this is how you do it) please let us know.
However, I did ask this myself some time back and got a big fat no
response )

Guddler.

---------------------------------------------
Guddler's Arcade
http://www.guddler.com

>

 

[Paul]

Re: [ukvac] monitor tech prob
cheers guddler
damn shame as its a brill game but its not the same with pink sea
paul

 

[DanP]

Re: [ukvac] monitor tech prob
Hi Paul, have you tried leaving the monitor in 'Purple' mode for a little
while (like a day or do)? The cabs in my 'room' need some time to adjust
to being rotated, I think it's got something to do with magnetic fields
(there a great big magnetic field in the RSJ holding up the room), and the
degausing circuits on the monitors. The going bad/going good phenomon also
happens to me when doing it as well. After a while they adjust and all the
colours are fine again.

Danny.

>From: "paul.vine" <paul.vine@ntlworld.com>
>Reply-To: ukvac@yahoogroups.com
>To: <ukvac@yahoogroups.com>
>Subject: [ukvac] monitor tech prob
>Date: Sat, 8 Sep 2001 13:47:06 +0100
>
>hi all
>
>ive got a 19" monitor (orion tube, hantarex chassis)
>as an example ive got a jamma 1943 on it and the colour of the sea is
>purply pink, but when i take the monitor out and rotate it slightly its
>perfect.
>ive checked the connections and all seems well
>its the same everytime, normal position its bad, start turning it and it
>goes perfect
>where do i start looking?
>
>any help much appreciated
>thanks
>paul
>
>
>

 

[JCRS]

Re: [ukvac] monitor tech prob
Have you check that the degaussing coil around the tube isnt slipping. or
pulled away from tube itself while its being moved ???
As far as I know this should be pulled up to as near as the front part of
the screen as possible to do its job properly when you switch the cab on.

Just my 2 pence..

Jcrs.

 

[Paul]

Re: [ukvac] monitor tech prob
thanks all for your suggestions, i'll give them all a try

thanks again
paul

 

[John Bennett]

RE: [ukvac] monitor tech prob
Guys,

I've had very similar problems with cocktail monitors in the past. The way
I figure it, it's due to problems with the degaussing circuit not kicking in
when
the power is applied, the monitor "get's used" to being in a particular
orientation
or position and moving it causes colour problems.

Have either of you tried manually degaussing the monitors? The correct way
to do this is with a degaussing coil - I know that some bods on the list
have
got these, but I've never been able to source one in this country.

There are alternatives (using a second monitor is one of the more arcane)
but my best results in the past have revolved around using a fridge magnet.
You can search the archives for Andy's original explanation of the trick
- try a search for "Andy Welburn" and then put aside fourteen weeks to
go through the posts but basically if you start with the magnet in the
centre of the screen between four & six inches from the glass tube and
rotate it in a spiral ending up about six inches outside the monitor you
should see some results.

Cheers
Chris
--
http://www.arcadenirvana.com - Gaming as it was meant to be...
http://www.ahchay.com - For all things Ahchay-related.

>

DATA Imported from archives: originally posted by Chris Ahchay (chris@arcadenirvana.com)

 

[d-type]

RE: [ukvac] monitor tech prob
From a very old memory, trying to fix tube magnetisation with a standard
(permanent) magnet is not a Good Thing. I seem to recall that it can distort
the monitor's shadow mask permanently, and you'll never be able to fix it.
(It's OK on a B&W tube as there is no shadow mask.)

You should use an AC magnetism source (like the de-gausser). The last telly
engineer I saw do it on a telly used the powersupply of his (big) soldering
iron. He waved it around near the screen. (And soldering irons can take a
relatively large amount of power.)

Most importantly, don't go too near the screen with it.

Have a look on Randy Fromm's monitor website, it'll probably tell you much
more.

Phillip Eaton (Forth-79/D-Type/Flip-Flop)
-------------------------------------------------------------------
Tel: +44 (0)1536 268424/504434 Fax: +44 (0)845 334 8195
Email: d-type@phillipeaton.com Mobile: +44 (0)7775 726366
Web: www.phillipeaton.com
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[colingrahamuk]

[ukvac] Re: monitor tech prob
My Hantarex does this as well when I rotate it to vertical - I think
this is caused by the shadow mask moving slightly in the tube.
Have a look at this FAQ.

http://www.repairfaq.org/REPAIR/F_monfaq2.html#MONFAQ_003

Regards,
Colin

 

[John Bennett]

[ukvac] Re: monitor tech prob
All TV tubes are aligned at the factory. If you adjust any of the
yoke magnets you'll likely end up with a purity error in one area
only. (and you'll have a job to get the magnets back to the right
positions!)

The fault you're describing sounds more like a dead degaussing coil.
Every time you switch on the tube gets degaussed (only takes a
second) by a coil of wire which runs round the perimeter. If this
fails the tube will still be magnetised in whatever orientation it
was last degaussed. There are all sorts of factors. The speaker is
one, even the Earth's magnetic field can be another - turn any
portable TV upside down and watch the result.

Simon



DATA Imported from archives: originally posted by (simon-marks@supanet.com)