On Monday, March 17, 2003 at 12:16:39 AM UTC+2, A. W. Jackson wrote:
I recently purchased a second-hand Commodore 1084S monitor to use with
my old videogame consoles (SNES, Saturn, etc.). I've tried the
monitor out and it is fully functional, but there's a slight flaw in
the picture. There are fuzzy vertical bars of slightly lighter/darker
brightness (most clearly visible against a black picture) near the
left edge of the screen, running the entire length of the screen from
top to bottom. The bars' position and size change when I adjust the
horizontal position and horizontal size knobs, so they're apparently
not actual phosphor burn-in (which leads me to hope that I might be
able to repair the problem). What kind of defect/damage might be
responsible for these bars, and is it repairable? I checked the
sci.electronics.repair TV repair and monitor repair FAQs and didn't
see anything that looked closely similar to my problem.
Also, I've been searching the web for information on this monitor, but
it seems that at different times (or in different territories)
Commodore sold several different monitors labelled "1084S", because
all the "1084S" documentation I've found on the web so far seems to be
for completely different monitors from mine. The monitor I have is a
"1084S-P" manafactured by Phillips in June 1988, according to the
label on the back. It has, for inputs, four RCA jacks (CVBS/L, C,
L.Audio and R.Audio), an 8-pin DIN for TTL RGB, and a 6-pin DIN for
analog RGB. There is also a plastic cover on the back which looks to
be the right shape and size for an SCART connector (possibly because
Commodore used the same case for both North American and European
versions of this monitor?) Also on the back are knobs for horizontal
position, horizontal size, vertical position, vertical size, a
pushbutton for switching between CVBS and LCA, and a pushbutton
labeled "VCR" whose function is unclear to me (nothing seems to change
on the screen when I push it). The front panel has knobs for hue,
brightness, contrast, color, sharpness, and volume, and a pushbutton
for switching between CVBS and RGB. Does anyone know where I can
download detailed information (such as a user's manual, or by some
miracle a schematic) for a "1084" matching this particular
description?
--Alex W. Jackson--

Hi Alex! Did you ever solve this? Having exactly the same issue with exactly the same monitor. Thank you in advance!

George Alibinisis wrote:
On Monday, March 17, 2003 at 12:16:39 AM UTC+2, A. W. Jackson wrote:
--Alex W. Jackson--

Hi Alex! Did you ever solve this? Having exactly the same issue
with exactly the same monitor. Thank you in advance!

Did you honestly think that replying to an 18 year old posting was likely
to get you anything more than insults?

Idiot.

In article ,
says...

On Monday, March 17, 2003 at 12:16:39 AM UTC+2, A. W. Jackson wrote:
I recently purchased a second-hand Commodore 1084S monitor to use with
my old videogame consoles (SNES, Saturn, etc.). I've tried the
monitor out and it is fully functional, but there's a slight flaw in
the picture. There are fuzzy vertical bars of slightly lighter/darker
brightness (most clearly visible against a black picture) near the
left edge of the screen, running the entire length of the screen from
top to bottom. The bars' position and size change when I adjust the
horizontal position and horizontal size knobs, so they're apparently
not actual phosphor burn-in (which leads me to hope that I might be
able to repair the problem). What kind of defect/damage might be
responsible for these bars, and is it repairable?

Hi Alex! Did you ever solve this? Having exactly the same issue with
exactly the same monitor. Thank you in advance!

It's been over 17 years since the original message was posted, so it's
unlikely that anyone remembers the result even if it did get fixed.

What have you tried so far to fix or narrow down the problem, if
anything?

It sounds like some kind of ghosting or ringing; is there a picture you
could upload anywhere (Imgur or similar) so we can see what it looks
like?

I'd start by swapping the video cable and also trying a different video
source, just to make sure it really is the monitor at fault. Then I'd
replace all electrolytic capacitors on general principle. These monitors
are decades old and there are probably multiple caps that have gone out
of spec by now, so just doing the whole lot can save multiple rounds of
troubleshooting.

There's a service manual for this monitor available at
http://www.zimmers.net/anonftp/pub/c...tics/monitors/. The scan
quality is poor, but it's certainly better than nothing.

Rayner

--
Big-8 Management Board: https://www.big-8.org
Homepage: http://magic-cookie.co.uk

On Monday, January 18, 2021 at 2:55:52 AM UTC+2, Rayner Lucas wrote:
In article ,
says...

On Monday, March 17, 2003 at 12:16:39 AM UTC+2, A. W. Jackson wrote:
I recently purchased a second-hand Commodore 1084S monitor to use with
my old videogame consoles (SNES, Saturn, etc.). I've tried the
monitor out and it is fully functional, but there's a slight flaw in
the picture. There are fuzzy vertical bars of slightly lighter/darker
brightness (most clearly visible against a black picture) near the
left edge of the screen, running the entire length of the screen from
top to bottom. The bars' position and size change when I adjust the
horizontal position and horizontal size knobs, so they're apparently
not actual phosphor burn-in (which leads me to hope that I might be
able to repair the problem). What kind of defect/damage might be
responsible for these bars, and is it repairable?

Hi Alex! Did you ever solve this? Having exactly the same issue with
exactly the same monitor. Thank you in advance!
It's been over 17 years since the original message was posted, so it's
unlikely that anyone remembers the result even if it did get fixed.

What have you tried so far to fix or narrow down the problem, if
anything?

It sounds like some kind of ghosting or ringing; is there a picture you
could upload anywhere (Imgur or similar) so we can see what it looks
like?

I'd start by swapping the video cable and also trying a different video
source, just to make sure it really is the monitor at fault. Then I'd
replace all electrolytic capacitors on general principle. These monitors
are decades old and there are probably multiple caps that have gone out
of spec by now, so just doing the whole lot can save multiple rounds of
troubleshooting.

There's a service manual for this monitor available at
http://www.zimmers.net/anonftp/pub/c...tics/monitors/. The scan
quality is poor, but it's certainly better than nothing.

Rayner

--
Big-8 Management Board: https://www.big-8.org
Homepage: http://magic-cookie.co.uk

Hi Rayner,

Firstly just wanna say to the Google Groups Einstein that the 18 year period doesn't matter as long as the problem was solved and the guy is still around on this earth. The Commode/Amiga retro-scene is very much alive.

Now I have posted lots of pics and info in this thread. I have already recapped the monitor and done a lot of measurements.

https://www.edaboard.com/threads/com...-lines.396322/

I thought I'd also ask here as Alex faced the exact same problem.

Thanks for your time Rayner.

You do need to know that the position of Village Idiot is occupied by an Australian at this time. Much as you might wish to compete, your status will remain "incurably stupid", only. You may re-apply should the incumbent leave.

On Monday, January 18, 2021 at 4:48:11 PM UTC+2, Peter W. wrote:
You do need to know that the position of Village Idiot is occupied by an Australian at this time. Much as you might wish to compete, your status will remain "incurably stupid", only. You may re-apply should the incumbent leave.

Get a life Peter instead of running stupidity contests in Google groups especially when you are the undisputed heavy weight champion. No way for the rest of us to win.

On Monday, January 18, 2021 at 1:24:24 PM UTC-5, wrote:
On Monday, January 18, 2021 at 4:48:11 PM UTC+2, Peter W. wrote:
You do need to know that the position of Village Idiot is occupied by an Australian at this time. Much as you might wish to compete, your status will remain "incurably stupid", only. You may re-apply should the incumbent leave.
Get a life Peter instead of running stupidity contests in Google groups especially when you are the undisputed heavy weight champion. No way for the rest of us to win.
George:

Then you are in full competition with Phil for the position? He may be relieved to know that.

On Monday, January 18, 2021 at 9:04:00 PM UTC+2, Peter W. wrote:
On Monday, January 18, 2021 at 1:24:24 PM UTC-5, wrote:
On Monday, January 18, 2021 at 4:48:11 PM UTC+2, Peter W. wrote:
You do need to know that the position of Village Idiot is occupied by an Australian at this time. Much as you might wish to compete, your status will remain "incurably stupid", only. You may re-apply should the incumbent leave.
Get a life Peter instead of running stupidity contests in Google groups especially when you are the undisputed heavy weight champion. No way for the rest of us to win.
George:

Then you are in full competition with Phil for the position? He may be relieved to know that.

you re not funny dude

In article ,
says...

Firstly just wanna say to the Google Groups Einstein that the 18 year
period doesn't matter as long as the problem was solved and the guy is
still around on this earth. The Commode/Amiga retro-scene is very much
alive.

Now I have posted lots of pics and info in this thread. I have already
recapped the monitor and done a lot of measurements.

https://www.edaboard.com/threads/com...or-with-faint-
vertical-lines.396322/

I thought I'd also ask here as Alex faced the exact same problem.

It's odd to see such an old thread get resurrected, but it is still a
relevant post even if the original participants are no longer reading,
so in this case I don't think it's anything to get worked up about.

I see from that edaboard thread that you've already tried the most
likely solutions :-(

The slowly drifting *horizontal* lines you mention sound like hum bars,
i.e. excessive voltage ripple from the power supply making its way onto
the display. If this is the case you'd see two bars on screen at once
(100Hz ripple from a full-wave rectifier, on a screen with 50Hz vertical
refresh) Again, by far the most common cause is a bad filter capacitor
in the low-voltage power supply, but there can be other components at
fault. See https://www.repairfaq.org/sam/monfaq.htm#monrwphb

If you have access to an oscilloscope, you might want to check the
outputs of the power supply for unusually high ripple. In particular,
the output of the 12V DC regulator (IC403) ought to look nice and
stable, as the regulator should smooth out whatever makes it past the
filter capacitor.

Obligatory safety note: be very careful and don't work alone, these
things have some nasty voltages inside them (including that 125V DC
power supply output). I highly recommend the safety guidelines at
https://www.repairfaq.org/sam/monfaq.htm#montrbs

Rayner

--
Big-8 Management Board: https://www.big-8.org
Homepage: http://magic-cookie.co.uk

On Tuesday, January 19, 2021 at 1:52:36 AM UTC+2, Rayner Lucas wrote:
In article ,
says...

Firstly just wanna say to the Google Groups Einstein that the 18 year
period doesn't matter as long as the problem was solved and the guy is
still around on this earth. The Commode/Amiga retro-scene is very much
alive.

Now I have posted lots of pics and info in this thread. I have already
recapped the monitor and done a lot of measurements.

https://www.edaboard.com/threads/com...or-with-faint-
vertical-lines.396322/

I thought I'd also ask here as Alex faced the exact same problem.
It's odd to see such an old thread get resurrected, but it is still a
relevant post even if the original participants are no longer reading,
so in this case I don't think it's anything to get worked up about.

I see from that edaboard thread that you've already tried the most
likely solutions :-(

The slowly drifting *horizontal* lines you mention sound like hum bars,
i.e. excessive voltage ripple from the power supply making its way onto
the display. If this is the case you'd see two bars on screen at once
(100Hz ripple from a full-wave rectifier, on a screen with 50Hz vertical
refresh) Again, by far the most common cause is a bad filter capacitor
in the low-voltage power supply, but there can be other components at
fault. See https://www.repairfaq.org/sam/monfaq.htm#monrwphb

If you have access to an oscilloscope, you might want to check the
outputs of the power supply for unusually high ripple. In particular,
the output of the 12V DC regulator (IC403) ought to look nice and
stable, as the regulator should smooth out whatever makes it past the
filter capacitor.

Obligatory safety note: be very careful and don't work alone, these
things have some nasty voltages inside them (including that 125V DC
power supply output). I highly recommend the safety guidelines at
https://www.repairfaq.org/sam/monfaq.htm#montrbs
Rayner

--
Big-8 Management Board: https://www.big-8.org
Homepage: http://magic-cookie.co.uk

thanks for all your efforts Rayner. I am using a 1:1 isolation transformer when I power up the monitor and I do have an oscope. Ill test the PSU although the lines are many more than two.. maybe 7-8 drifting to the bottom of the screen. Thing is that there are brand new caps everywhere.

I read around the internet and there was this thread and just one more guy with same monitor, same issue. He told me on eab boards via private message that his monitor is with an expert at the moment.

it definetely looks like some harmonic but my knowledge in CRTs is very little at the moment - learning every day.

In article ,
says...

thanks for all your efforts Rayner. I am using a 1:1 isolation
transformer when I power up the monitor and I do have an oscope. Ill
test the PSU although the lines are many more than two.. maybe 7-8
drifting to the bottom of the screen. Thing is that there are brand
new caps everywhere.

I read around the internet and there was this thread and just one more
guy with same monitor, same issue. He told me on eab boards via
private message that his monitor is with an expert at the moment.

it definetely looks like some harmonic but my knowledge in CRTs is
very little at the moment - learning every day.

Okay, if there are 7-8 lines it's not mains frequency. I'd say it's
still worth checking the PSU output voltages for stability, though - it
will help to know whether you can rule that section out or not.

The number of horizontal lines suggests the unwanted oscillation has a
350 - 400Hz component, which might be a helpful clue.

If investigating the PSU doesn't reveal anything, here's how I'd look at
it. You've got a scope and a schematic annotated with expected voltages
and waveforms. The problem shows up on the display, therefore it must be
present among the signals and voltages that go to the CRT and deflection
yoke. If you can figure out which one(s), you can then trace it back to
the origin from there.

It seems highly unlikely to be anything to do with the EHT or the focus
grid voltage, which is good because those are the ones I'd least like to
be messing with.

It doesn't look much like a deflection problem either, as from the
pictures on the edaboard thread I can't see any actual distortion to the
image on screen.

As far as I can see, that mostly just leaves the:

+12V line
+125V line
-20V line
RGB signal lines

going to the CRT neck board as the likely candidates.

The safety guidelines at
https://www.repairfaq.org/sam/monfaq.htm#montrbs include some advice for
staying safe when investigating a running monitor; I particularly
recommend the bit about only ever connecting/disconnecting test leads
when the monitor is unpowered and unplugged.

Let us know if you manage to narrow it down.

Rayner

--
Big-8 Management Board: https://www.big-8.org
Homepage: http://magic-cookie.co.uk