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| Author |
Message |
scg
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Monitor problem
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Apr 2 08:15 UTC 1998 |
A few minutes ago, the picture on my monitor suddenly became very small
(moving from the whole screen to the middle of the screen), very flickery,
and very wavy. I tried turning the monitor off and back on, to see if that
would help. When I turned it back on, it had the same problem for maybe 10
more seconds, and then, with a loud clicking sound, the picture disappeared
completely. After that, it was making a faint clicking noise a little more
than once a second. I also started noticing an electrical burning smell.
I turned it off and unplugged it, and plugged the monitor from the console
of my FreeBSD box (which almost never gets used) into the Windows box. That
works, but is constantly reminding me of why I bought the nicer monitor for
the Windows box a few years ago.
Is my monitor dead, or is there something fixable that would be likely to
cause this problem? It's close to three years old, so I'm assuming it's not
still under warranty.
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| 64 responses total. |
scott
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response 1 of 64:
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Apr 2 11:50 UTC 1998 |
If it's a 17" or bigger, it's probably worth fixing. Most likely it is a
problem with the support electronics, rather than the tube itself.
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n8nxf
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response 2 of 64:
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Apr 2 12:52 UTC 1998 |
The faint clicking noise you hear is the power supply going into overload
protection. It usually means that something downstream shorted out.
Perhaps a capacitor or the flyback transistor and / or transformer. I'd
guess about $100 or more to get it fixed.
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rtgreen
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response 3 of 64:
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Apr 7 05:30 UTC 1998 |
before you spend any money, open the case and give it a good cleaning.
I've resurrected monitors which exhibit a regular 'clicking', discovering
that the accumulated dust was making a fine path to ground for the HV,
bypassing the tube. Clean well, after carefully discharging any residual
charge on the CRT anode, and try it again.
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arthurp
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response 4 of 64:
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Apr 16 02:34 UTC 1998 |
But as you clean it look for smoking guns. If you can find a heat
damaged area, you have a pretty good clue what died. I did this to fix
my mono monitor. It worked great for several months until a different
component blew. I have yet to look at it this time.
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scg
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response 5 of 64:
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Apr 16 03:14 UTC 1998 |
Thanks. I've got a monitor I borrowed from work, that I'm using for the
moment. It will be wanted back eventually, so I do need to do something.
The one that died was a 15" monitor, that was out of warranty by about nine
or ten months. If it's likely to cost $100 or more to fix it, I should
probably spend $300 on a new monitor, with a warranty.
I may also take it apart and look at it. I should figure out what the parts
that need to be carefully discharged are before I do that.
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n8nxf
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response 6 of 64:
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Apr 16 10:56 UTC 1998 |
You really don't have to discharge anything unless you go to pull the tube
of the flyback transformer. The flyback is the plastic tower with a thick
wire running to the tube, terminating under a suction cup on the side of
the tube. When running, it will have 20,000 to 40,000 volts on it. Not
enough current to kill you, most likely, however, enough to knock you on
your ass and remind you that electricity can hurt.
The picture tube acts as a capacitor that can hold this charge for a
while. If you are going to poke around this second anode, it is a good
idea to discharge it. Simply clip one end of a wire to the bare wire
running around the back of the tube and the other end to a long, skinny,
screwdriver. Then slide the end of the screwdriver under the suction
cup thingy, holding the screwdriver by its plastic handle, and make
contact with the metal clip. If you hear a snap, it's discharged. If
you don't it's probably discharged or your screwdriver isn't grounded.
If the monitor has been off for a while, it will discharge on its own
and you won't hear the snap.\
You only have to discharge the tube if you need to break the second
anode connection. Otherwise don't worry about it.
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rcurl
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response 7 of 64:
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Aug 25 16:18 UTC 1999 |
My Apple Multiple Scan 15" monitor has recently started to have intermittent
wobblies - some darker waves move rapidly down the display, which also
twists slightly. These events last a fraction of a second, and occur
several times per hour. No sound accompanies the events. Am I on the
verge of losing it? It is nearly 3 years since purchase, so I presume
it is out of warranty, and I can safely (?!) fiddle inside: suggestions?
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wlevak
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response 8 of 64:
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Aug 25 18:03 UTC 1999 |
More than the tube and the flyback have high voltage on them. If you don't
know which does, do not go messing around inside the monitor. There
definitely is enough stored electricity inside a monitor to kill you under
the right conditions. If you don't know what the right conditions are, you
have no business inside a monitor.
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gull
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response 9 of 64:
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Aug 25 19:25 UTC 1999 |
Re #7: Have you moved it recently? In my dorm I get that effect when
someone turns on a fluorescent light that's directly on the other side of
the wall -- the ballest's magnetic field interacts with the one from the
CRT. Maybe a similar thing is going on with yours.
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rcurl
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response 10 of 64:
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Aug 26 06:04 UTC 1999 |
No, it is in the same location as ever. I did install a new UPS, and
vaguely wondered if that could be giving me wobbly voltage. Is a
UPS "straight through" when it isn't UPSing, or is the power always
going through the power conversion?
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gull
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response 11 of 64:
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Aug 26 16:49 UTC 1999 |
Depends. The cheap ones are usually "straight through" - they're referred
to as "off line" UPS's. Big, expensive ones are sometimes "on line" UPS's,
which means they're always doing power conversion. This gives better spike
protection and voltage regulation, since the UPS is basically generating its
own AC independent of what the power company sends you.
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gull
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response 12 of 64:
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Aug 26 16:58 UTC 1999 |
A thought -- you didn't put the UPS next to the monitor, did you? If you
did, move it and see if your problem goes away. I suppose most UPS units
probably have switching power supplies now, but I've seen some that had
regular transformers and would kick out a pretty good magnetic field when
they decided to switch into charge or self-test mode.
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rcurl
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response 13 of 64:
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Aug 26 20:06 UTC 1999 |
The UPS is about 2 feet from the monitor (center-to-center). It is a
Tripp-Lite 625. The wobblies did not occur yesterday or (so far) today.
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rcurl
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response 14 of 64:
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Oct 15 22:25 UTC 1999 |
The wobblies receded, but a new problem has appeared. Fibrillation on
changing resolution. This occurred just after I had installed MacOS 6 so I
thought I had a problem with an old driver, so I downloaded the new Apple
Display, but it didn't work: fibrillation consists of the picture breaking
into three pieces that flash on and off very rapidly, when I change
resolution. I was in 640x480 and switched to 832x624, but when I swtiched
back it fibrillated. I can now only get it into 832x624 and 512x384, while
trying to get to 640x480 and 800x600 is no longer possible.
When one switches resolution the monitor clicks as though a relay is
working. What is that? It no longer clicks when I attempt to get into the
now "forbidden" resolutions. I had a chat with an Apple Care person,
wholed led me through all of the protocols he could think of for fixing
this, but nothing worked. He suggested I take the monitor in to be looked
at.
Is this a home-repairable fault? In fact, is it in software or in the
hardware?
(I may pick up a replacement monitor at UM PD - is there a way to
test a monitor there without bringing in a CPU?)
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n8nxf
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response 15 of 64:
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Oct 18 11:31 UTC 1999 |
Get lucky and use one you find there.
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rcurl
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response 16 of 64:
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Oct 25 04:50 UTC 1999 |
Right - I can always donate it to Kiwanis if it doesn't work. 8^}
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rcurl
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response 17 of 64:
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Oct 27 17:00 UTC 1999 |
I took Klaus' advice and bought another Apple MultiScan 15 from
PD. I only had a few minutes to check it, but did connect it to
a computer they had on their workbench and it did work and show
640x480 resolution. I replaced the troubled one with it....and
it exhibits the same problem! Fibrillation started after it was on
for a bit. So, this is a generic old-age problem. Where do you
think I should look in the 'guts', Klaus? At least I have an operable
monitor (at 832x624) while I look into the problem on the 'old' one.
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n8nxf
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response 18 of 64:
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Oct 28 11:40 UTC 1999 |
Ar you sure it's the monitor? Could be the video driver.
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rcurl
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response 19 of 64:
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Oct 28 18:24 UTC 1999 |
That has occurred to me, but I'm not sure what evidence I have to
distinguish a monitor problem from a video driver problem. What and where
is the video driver - hardware or software? I replaced the software driver
with the most recent version, with no effect. Is there a video chip? The
problems shown by the two monitors are similar but significantly different
- e.g., the old monitor went into fibrillation immediately at 640x480. The
'new' (old) monitor showed a distortion of X-Y size at 640x480 that could
not be fully corrected, and then started to "wobble" as the old one had
before fibrillation started. What is completely common is that both won't
work in 640x480 resolution.
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rcurl
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response 20 of 64:
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Oct 28 18:34 UTC 1999 |
Oh - another thing that is peculiar is that there is no problem in 640x480
when the computer is booted up from the system installer CD-ROM. That
would suggest it is NOT the monitor. I have a video PCI card installed and
I've wondered about that - an Xclaim VR accelerator, video capture, and
other goodies card. The monitor plugs into that card, not the CPU monitor
port. I also reinstalled the ATI software (also updated) when this problem
began. Hmmm...maybe I should plug the monitor into the original port and
see what happens....
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rcurl
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response 21 of 64:
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Oct 29 04:06 UTC 1999 |
....so did that, and lo-and-behold, no wobblies, fibrillation, or
other problems at 640x480. So I cleaned and reseated the video card,
but that did not improve matters. But it appears the problem is in
the ATI video card. I've sent them a description of the problem - might
get a new card, since it has a 5 year warranty. And I have a spare
monitor, which is probably OK! This has been quite an exercise in
both frustration and detection. I thank those, especially Klaus, that
submitted suggestions: it was his suggestion to look at the *driver*
that fortified my checking the video card.
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scott
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response 22 of 64:
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Oct 29 13:06 UTC 1999 |
...or maybe you can plug both in, and double your screen space?
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rcurl
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response 23 of 64:
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Oct 29 18:09 UTC 1999 |
How about stereo? :)
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rcurl
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response 24 of 64:
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Nov 6 06:41 UTC 1999 |
My MultiScan 15 monitor problem appears to be solved. It isn't the
monitor: it was the ATI video board *driver* (one of Klaus' guesses).
I had reinstalled the driver (with extensions off), which didn't help,
but ATI said to first trash every ATI* extension and then reinstall
the driver. This seems to have done the trick. The 'owners manual' for
the board says nothing about *re*installing the driver, nor does the
installer have an uninstall mode. You just have to know (or ask, or
try things out at random.....).
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