1084S monitor problem

Jan · 19 April 2003, 22:18

I have a little problem with my 1084S monitor here.

Recently the monitor started to develop thin diagonal lines moving across the screen from the bottom right to the top left corner. The screen is full of it, it is a constant "flow". This annoys me, I get a headache after some time looking at it.

Note that this only happens in RGB mode. It does not appear in the CVBS mode which I use for my C64. So I can use the monitor without problems with my C64, but not with my Amiga...

I am using a DIN cable, not the SCART, because my 1084S does not have a SCART plug.

Any idea what I can do to repair this? I don't want to buy another monitor from Ebay, I have a 1081 in the basement, but this one sucks when using it with the C64.

Severin · 19 April 2003, 23:19

Quick check, bang it on the side a few times (with your palm, not a hammer), if it causes any difference then it's just a dry joint, fairly simple to fix.

If not check your cable, plug the amiga into a TV etc...

If it does need repairing, take it to a TV repair place not a computer one...

Overdoc · 20 April 2003, 00:29

Sounds like a problem in the cable to me.
CVBS and Y/C modes ( like when you plug your C64 in ) are transformed to RGB internally. So if there actually was a problem in the RGB circuit, then you would also have this problem when running from CVBS or Y/C.
Try moving the cable around while viewing the picture. Does it change anything ?
Also, maybe you have some device stading near the monitor which causes some interference with the cable, computer or monitor ?

If nothing helps then check if the problem stays on the 1081, too ? ( with same cable and same Amiga )
The problem could also be on the Amiga side ! Check if it also is there when you connect the Amiga via it's b/w mono-out to the 1084's CVBS-in ?

Let me know what you found out

Jan · 20 April 2003, 00:48

Thanks for your replies!

First of all, I don't have this problem with my 1081, but I'm using a different cable there, the 1081 only has a SCART plug.

It all worked fine until a couple of weeks ago when this all started... I had the 1084S in my basement for some time (dry place, well wrapped) and brought it back to my desk because I needed a monitor that could handle both the Amiga and the C64. The monitor worked well when I put it into the basement, but when I got it back there were these diagonal lines...

I have the DIN cable and the C64 monitor cable (3x cinch) plugged in simultaneously, so I only have to push the CVBS button at the front panel to switch between Amiga and C64.

The Amiga works just fine, I checked it with the 1081.

Banging on the side did not help

Overdoc · 20 April 2003, 21:42

Hmm, does it also happen if you disconnect the C64 3-chinch cable ? Could it be a grounding problem ?

Another question:
How do you have connected Amiga audio l&r and C64 audio at the same time ? I think you have to connect/disconnect these when switching from one to the other because there are only 2 audio ports on the 1084 ! Maybe you are doing something wrong here ?

If nothing helps then I think the problem can only be along the way from the RGB connector to the big IC inside the 1084 which provides R, G and B for the tube and splits composite video into RGB.

Jan · 21 April 2003, 01:10

Nothing changes when I unplug the three cinch plugs for the C64.

Since only one of the 1084S speakers is working at the moment, I am using the PC loudspeakers for the Amiga sound and the 1084S (well, no "S" anymore

) speaker for the C64 (which is only producing mono sound anyway). So, for the C64, sound and picture are reproduced by the 1084S, and for the Amiga, sound is reproduced by PC speakers and picture is reproduced by the 1084S. It works fine this way, nothing has to be unplugged or changed, if only the Amiga picture was without those diagonal lines!

Is this a case where some spots have to be re-soldered like in the 1081?

Any idea?

Overdoc · 21 April 2003, 22:38

1081 and 1084 are very similar and also on some 1084 often solder joints especially on the flyback transformer have to be re-soldered.
But this is not the problem in your case ! If this was the problem then you would have intermittent picture loss, both in RGB and CVBS mode !

Both the RGB and the CVBS input end up at the big IC in the 1084, and from there go to the tube.
So, since your CVBS input works without problems, the problem can only be between the RGB input and the big IC, or in the cable or connector !

If you have a multimeter than you can check the cable. Maybe there is a shortcut between 2 or more wires in it ?

Also, maybe the round DIN connector in the 1084 has a bad solder joint ? I think I had similar problems with a bad solder joint on a connector one time.
Maybe even the bad speaker has lost a cable which is now shortening something inside the monitor ? Who knows ?

Anyway, when opening the monitor be careful not to touch anything around the high voltage !! There can be thousands of volts in the tube even after the monitor is plugged off !! This voltage could be deadly !!
So, only look at the back of the board where the connector is soldered in and resolder it. That might help.

And, for safety, only use one hand when you touch anything inside the monitor. This way you can be save from a dangerous electrical strike ( you might feel it but it won't kill you

)

Jan · 22 April 2003, 00:25

Okay, I will check everything between the IC and the RGB input. Maybe I'll see something, but I doubt it (it's never that easy). Unfortunately I don't have any chance to check the cable, and there is no other option to test it somewhere else. It was hard to find such a cable since the monitor came without it when I got it, and if it's broken then I'm gonna be really pissed.

Also, I'll tie my left hand to my back to make sure I survive this

.

Shadowfire · 22 April 2003, 01:54

... just as a curiosity, are you running your Amiga video cable next to any power cables?

Jan · 22 April 2003, 09:42

No, not really. The only power cable in the near vicinity is the monitor's own.

Jan · 07 May 2003, 20:57

Shoot!!

It's not the cable, it's not the monitor..... it's my A1000!

My little baby

I checked a different Amiga with the same cable and monitor, and those diagonal moving lines disappeared!

Can somebody help? What could be the problem with the A1000?

Overdoc · 07 May 2003, 22:00

Hehe, I knew the problem was more likely to be external than inside the monitor

What I would check first would be the monitor connector on the A-1000. There could be some bad solder joint there !

Seems like you are really hunted by some hardware destroying ghost !! I have never heard of anyone having so much bad luck with all his Commodores than you, Jan !
My thoughts are with you and your poor Commies

Jan · 07 May 2003, 22:09

Hehe thanks, but most of my computers are working again, this is the last hardware problem I have

.

Hmm I cannot see any bad solder joints, however I can resolder them just to make sure.

Could it also be that a chip is broken?

Overdoc · 08 May 2003, 19:36

Bad solder joints sometimes cannot be seen ! At least not without magnifying glass and strong light.
Soldering them again wouldn't be wrong, I'd say

If it doesn't help then I would say the problem must be somewhere in the video circuit. Could be some problem with Denise. I don#t know much about the A-1000, but I am not sure if an A-500 Denise is the same like in the A-1000 ? I think they are different, but I am not sure - maybe it's the Agnus chip I remember as being different ?
Also, are you sure there is nothing interfering with the cable or with the monitor itself ? Maybe the monitor is standing on top of the A-1000 and gets interferred with the 1000's psu, while when you connect an A-500 the psu is more far away ?

Jan · 09 May 2003, 09:56

I resoldered the joints, but it didn't help (I only resoldered the ones from the RGB connector). I also swapped the Denise with one from my A500 (they are the same), nothing changed, so the chip is okay.

The monitor is standing on a shelf, not directly on the A1000. And the PSU of the A1000 is directly next to the RGB connector

, but since that has worked for years, I don't think it is a problem. And I can't change it since the PSU is an internal one.

Hmmm, I'm running out of ideas here. The monitor and cable are okay, the Denise chip is also okay, and I resoldered the RGB connector. Is there anything more I can do?

Jan · 12 May 2003, 23:17

To make things more confusing, here's what I found out when I tested two monitors and two Amigas:

1) the A1000 + DIN cable + 1084S monitor = diagonal moving lines
2) the A1000 + SCART cable + 1081 monitor = working perfectly (!)
3) an A500 + DIN cable + 1084S monitor = working perfectly
4) an A500 + SCART cable + 1081 monitor = working perfectly.

Can anybody explain this? Note that I can't use the DIN cable in the 1081 or the SCART cable in the 1084S, there are no connectors. But the cable doesn't seem to be the problem anyway.

Shadowfire · 13 May 2003, 01:18

the RF encoder on the A1000 is f**ed

<edit> Oh wait a minute, DIN connector? that's RGB right?

Jan · 13 May 2003, 09:48

Yes, it's RGB. The 1084S has a CVBS mode for my C64 and a RGB mode for my Amiga, that's why I want to keep the monitor because I can use it with both computers. The 1081 produces a crappy picture with the C64.

I have no explanation for this... the Amiga works fine with the 1081, but not with the 1084S??

19 April 2003, 22:18	#1
Jan Junior Member Join Date: Aug 2002 Location: here Posts: 140	1084S monitor problem I have a little problem with my 1084S monitor here. Recently the monitor started to develop thin diagonal lines moving across the screen from the bottom right to the top left corner. The screen is full of it, it is a constant "flow". This annoys me, I get a headache after some time looking at it. Note that this only happens in RGB mode. It does not appear in the CVBS mode which I use for my C64. So I can use the monitor without problems with my C64, but not with my Amiga... I am using a DIN cable, not the SCART, because my 1084S does not have a SCART plug. Any idea what I can do to repair this? I don't want to buy another monitor from Ebay, I have a 1081 in the basement, but this one sucks when using it with the C64.

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19 April 2003, 23:19	#2
Severin Registered User Join Date: Dec 2002 Location: Gloucester / UK Posts: 700	Quick check, bang it on the side a few times (with your palm, not a hammer), if it causes any difference then it's just a dry joint, fairly simple to fix. If not check your cable, plug the amiga into a TV etc... If it does need repairing, take it to a TV repair place not a computer one...

20 April 2003, 00:29	#3
Overdoc Commodore Collector Join Date: Aug 2001 Location: Austria Age: 53 Posts: 944	Sounds like a problem in the cable to me. CVBS and Y/C modes ( like when you plug your C64 in ) are transformed to RGB internally. So if there actually was a problem in the RGB circuit, then you would also have this problem when running from CVBS or Y/C. Try moving the cable around while viewing the picture. Does it change anything ? Also, maybe you have some device stading near the monitor which causes some interference with the cable, computer or monitor ? If nothing helps then check if the problem stays on the 1081, too ? ( with same cable and same Amiga ) The problem could also be on the Amiga side ! Check if it also is there when you connect the Amiga via it's b/w mono-out to the 1084's CVBS-in ? Let me know what you found out

20 April 2003, 00:48	#4
Jan Junior Member Join Date: Aug 2002 Location: here Posts: 140	Thanks for your replies! First of all, I don't have this problem with my 1081, but I'm using a different cable there, the 1081 only has a SCART plug. It all worked fine until a couple of weeks ago when this all started... I had the 1084S in my basement for some time (dry place, well wrapped) and brought it back to my desk because I needed a monitor that could handle both the Amiga and the C64. The monitor worked well when I put it into the basement, but when I got it back there were these diagonal lines... I have the DIN cable and the C64 monitor cable (3x cinch) plugged in simultaneously, so I only have to push the CVBS button at the front panel to switch between Amiga and C64. The Amiga works just fine, I checked it with the 1081. Banging on the side did not help

20 April 2003, 21:42	#5
Overdoc Commodore Collector Join Date: Aug 2001 Location: Austria Age: 53 Posts: 944	Hmm, does it also happen if you disconnect the C64 3-chinch cable ? Could it be a grounding problem ? Another question: How do you have connected Amiga audio l&r and C64 audio at the same time ? I think you have to connect/disconnect these when switching from one to the other because there are only 2 audio ports on the 1084 ! Maybe you are doing something wrong here ? If nothing helps then I think the problem can only be along the way from the RGB connector to the big IC inside the 1084 which provides R, G and B for the tube and splits composite video into RGB.

21 April 2003, 01:10	#6
Jan Junior Member Join Date: Aug 2002 Location: here Posts: 140	Nothing changes when I unplug the three cinch plugs for the C64. Since only one of the 1084S speakers is working at the moment, I am using the PC loudspeakers for the Amiga sound and the 1084S (well, no "S" anymore ) speaker for the C64 (which is only producing mono sound anyway). So, for the C64, sound and picture are reproduced by the 1084S, and for the Amiga, sound is reproduced by PC speakers and picture is reproduced by the 1084S. It works fine this way, nothing has to be unplugged or changed, if only the Amiga picture was without those diagonal lines! Is this a case where some spots have to be re-soldered like in the 1081? Any idea?

21 April 2003, 22:38	#7
Overdoc Commodore Collector Join Date: Aug 2001 Location: Austria Age: 53 Posts: 944	1081 and 1084 are very similar and also on some 1084 often solder joints especially on the flyback transformer have to be re-soldered. But this is not the problem in your case ! If this was the problem then you would have intermittent picture loss, both in RGB and CVBS mode ! Both the RGB and the CVBS input end up at the big IC in the 1084, and from there go to the tube. So, since your CVBS input works without problems, the problem can only be between the RGB input and the big IC, or in the cable or connector ! If you have a multimeter than you can check the cable. Maybe there is a shortcut between 2 or more wires in it ? Also, maybe the round DIN connector in the 1084 has a bad solder joint ? I think I had similar problems with a bad solder joint on a connector one time. Maybe even the bad speaker has lost a cable which is now shortening something inside the monitor ? Who knows ? Anyway, when opening the monitor be careful not to touch anything around the high voltage !! There can be thousands of volts in the tube even after the monitor is plugged off !! This voltage could be deadly !! So, only look at the back of the board where the connector is soldered in and resolder it. That might help. And, for safety, only use one hand when you touch anything inside the monitor. This way you can be save from a dangerous electrical strike ( you might feel it but it won't kill you )

22 April 2003, 00:25	#8
Jan Junior Member Join Date: Aug 2002 Location: here Posts: 140	Okay, I will check everything between the IC and the RGB input. Maybe I'll see something, but I doubt it (it's never that easy). Unfortunately I don't have any chance to check the cable, and there is no other option to test it somewhere else. It was hard to find such a cable since the monitor came without it when I got it, and if it's broken then I'm gonna be really pissed. Also, I'll tie my left hand to my back to make sure I survive this .

22 April 2003, 01:54	#9
Shadowfire Registered User Join Date: Aug 2001 Location: Connecticut USA Posts: 617	... just as a curiosity, are you running your Amiga video cable next to any power cables?

22 April 2003, 09:42	#10
Jan Junior Member Join Date: Aug 2002 Location: here Posts: 140	No, not really. The only power cable in the near vicinity is the monitor's own.

07 May 2003, 20:57	#11
Jan Junior Member Join Date: Aug 2002 Location: here Posts: 140	Shoot!! It's not the cable, it's not the monitor..... it's my A1000! My little baby I checked a different Amiga with the same cable and monitor, and those diagonal moving lines disappeared! Can somebody help? What could be the problem with the A1000?

07 May 2003, 22:00	#12
Overdoc Commodore Collector Join Date: Aug 2001 Location: Austria Age: 53 Posts: 944	Hehe, I knew the problem was more likely to be external than inside the monitor What I would check first would be the monitor connector on the A-1000. There could be some bad solder joint there ! Seems like you are really hunted by some hardware destroying ghost !! I have never heard of anyone having so much bad luck with all his Commodores than you, Jan ! My thoughts are with you and your poor Commies

07 May 2003, 22:09	#13
Jan Junior Member Join Date: Aug 2002 Location: here Posts: 140	Hehe thanks, but most of my computers are working again, this is the last hardware problem I have . Hmm I cannot see any bad solder joints, however I can resolder them just to make sure. Could it also be that a chip is broken?

08 May 2003, 19:36	#14
Overdoc Commodore Collector Join Date: Aug 2001 Location: Austria Age: 53 Posts: 944	Bad solder joints sometimes cannot be seen ! At least not without magnifying glass and strong light. Soldering them again wouldn't be wrong, I'd say If it doesn't help then I would say the problem must be somewhere in the video circuit. Could be some problem with Denise. I don#t know much about the A-1000, but I am not sure if an A-500 Denise is the same like in the A-1000 ? I think they are different, but I am not sure - maybe it's the Agnus chip I remember as being different ? Also, are you sure there is nothing interfering with the cable or with the monitor itself ? Maybe the monitor is standing on top of the A-1000 and gets interferred with the 1000's psu, while when you connect an A-500 the psu is more far away ?

09 May 2003, 09:56	#15
Jan Junior Member Join Date: Aug 2002 Location: here Posts: 140	I resoldered the joints, but it didn't help (I only resoldered the ones from the RGB connector). I also swapped the Denise with one from my A500 (they are the same), nothing changed, so the chip is okay. The monitor is standing on a shelf, not directly on the A1000. And the PSU of the A1000 is directly next to the RGB connector , but since that has worked for years, I don't think it is a problem. And I can't change it since the PSU is an internal one. Hmmm, I'm running out of ideas here. The monitor and cable are okay, the Denise chip is also okay, and I resoldered the RGB connector. Is there anything more I can do?

12 May 2003, 23:17	#16
Jan Junior Member Join Date: Aug 2002 Location: here Posts: 140	To make things more confusing, here's what I found out when I tested two monitors and two Amigas: 1) the A1000 + DIN cable + 1084S monitor = diagonal moving lines 2) the A1000 + SCART cable + 1081 monitor = working perfectly (!) 3) an A500 + DIN cable + 1084S monitor = working perfectly 4) an A500 + SCART cable + 1081 monitor = working perfectly. Can anybody explain this? Note that I can't use the DIN cable in the 1081 or the SCART cable in the 1084S, there are no connectors. But the cable doesn't seem to be the problem anyway.

13 May 2003, 01:18	#17
Shadowfire Registered User Join Date: Aug 2001 Location: Connecticut USA Posts: 617	the RF encoder on the A1000 is f**ed <edit> Oh wait a minute, DIN connector? that's RGB right?

13 May 2003, 09:48	#18
Jan Junior Member Join Date: Aug 2002 Location: here Posts: 140	Yes, it's RGB. The 1084S has a CVBS mode for my C64 and a RGB mode for my Amiga, that's why I want to keep the monitor because I can use it with both computers. The 1081 produces a crappy picture with the C64. I have no explanation for this... the Amiga works fine with the 1081, but not with the 1084S??

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