Help with Amiga 1080 monitor

[walterg74]

Hi all,

Recently picked up an Amiga 1080 monitor.

I was about to post something about it that puzzles me, for any. Onitor experts that know the insides, but now I also have to ask a second more important question regarding function...

Here goes #1:

I tested the monitor out with an Amiga, analog RGB mode. All works fine, except minor image adjust,ents normal for the age I guess and that I presume can be tweaked if one knows how, but the image in general, brightness, colors, etc., all great.

Today, I was testing something unrelated wich is replacing the PLA chip on a C64, and decided to try it out with this same monitor.

Whe I got a black screen I thought "oh great, I was sold a non-working PLA". But then I connected the exact same video cable that was going to the monitor to the composite input of my kitchen TV, and the image appeared as it should...

So it seems that the composite and chroma/luma inputs of the monitor are not working!

I have both cable types for the C64, the one that outputs composite and the ine that outputs separate chroma/luma. I have tried both. I also set the switch at the front to the correct positions depending on what I hook up and nothing. All I get is a black screen... What gives?


Here is #2:

When I received the monitor, I hear a rattling noise inside... thought "uh oh, that can't be good..."
tested it anyway (of course) and seemed to work fine.
Now that I am back home (purchased it on a trip, by the way) I decided to take te case apart to see what this was...
What I found was the piece shown on the attached screenshot. This seems to be a piece that is held on to something with a scree, and the black piece that the screw goes into, seems to have broken off somwhere.

Now the mysterious thing is... I searched EVERYWHERE inside the case and I am not able to see anything even remotely resembling what this mught be a part of... not even of the same exact color... so again I guess, what the hell? This ine is probably for the even more experts

Appreciate your help!

[walterg74]

Forgot the attachments for #2...

Here they are.

[paul1981]

It looks like a support for a video connector or such, despite there not being one. Actually, I've changed my mind - it looks like it could just be a case support for the rear right side. Have a look in the photo I found; you will see it screws to the top of the line output transformer (black thing on right side). Bear in mind there are lethal voltages inside a tv and monitor even with the power off. Don't touch the tube! Don't touch anything! The only thing you'll want to touch if needed would be the focus knob with a flat blade screwdriver (plastic to be safe) on the back of that transformer to get a crisper picture if need be. You'll need a big mirror though as you're dicing with death if you try and reach around it with your arms to adjust it whilst looking directly at the screen. Don't risk it, use a mirror.



Ref:
http://www.oldcomputr.com/commodore-amiga-1000-1985/

[walterg74]

It looks like a support for a video connector or such, despite there not being one. Actually, I've changed my mind - it looks like it could just be a case support for the rear right side. Have a look in the photo I found; you will see it screws to the top of the line output transformer (black thing on right side). Bear in mind there are lethal voltages inside a tv and monitor even with the power off. Don't touch the tube! Don't touch anything! The only thing you'll want to touch if needed would be the focus knob with a flat blade screwdriver (plastic to be safe) on the back of that transformer to get a crisper picture if need be. You'll need a big mirror though as you're dicing with death if you try and reach around it with your arms to adjust it whilst looking directly at the screen. Don't risk it, use a mirror.


Ref:
http://www.oldcomputr.com/commodore-amiga-1000-1985/

Thanks Paul!

That seems to be exactly it!  Given the circumstances though, and the fact that it does not really do much, i guess I will consider just leaving it out, at least fot now.

I did see the two knobs there, but not sure what they are for. I am a bit dissapointed with the vertical height, which it were a simpler knob, and the lack of a horizontal equivalente, and of a vertical position too.
A weird thing I experienced is I'll get the workbench correctly alligned when it loads (from CF) and centered, and when I launch a game it's shifted a little to the right...

[paul1981]

Thanks Paul!

That seems to be exactly it!  Given the circumstances though, and the fact that it does not really do much, i guess I will consider just leaving it out, at least fot now.

I did see the two knobs there, but not sure what they are for. I am a bit dissapointed with the vertical height, which it were a simpler knob, and the lack of a horizontal equivalente, and of a vertical position too.
A weird thing I experienced is I'll get the workbench correctly alligned when it loads (from CF) and centered, and when I launch a game it's shifted a little to the right...

Some games are off centre in either or both directions which is obviously down to the programmer of the game. To correctly set up your monitor for your Amiga (any Amiga) you should just have a standard Workbench screen open and make sure your overscan/screenmode settings are both set to default and PAL (or NTSC if you live in those parts and intend to run NTSC games). This is your reference - Workbench default settings...before anyone mucks about with overscan or screen position. Then adjust your monitor settings to match that. Or, open Deluxe paint in 320x256 or 640x256 (again, Workbench overscan and screenmode prefs MUST be default here) and fill the whole screen with a mid grey and then adjust, or draw a white border or something. Or, use a test pattern generator program (some on aminet) or test image. You should leave some gap though to account for overscan, which many games use along with graphics/video utilities.

If you don't have certain controls on your monitor, then they will be on the circuit board somewhere and there will be pots to adjust. Again, all very dangerous working on live equipment and I don't recommend it to be honest. The other knob on the back of the LOPT/transformer will be the screen voltage. No need to touch this, but if you do don't worry just put it back to where it was. Again, CRT monitors / tv's are extremely dangerous with their thousands upon thousands of VOLTS. Don't take any risks, it can easily kill you.

[Matt_H]

Not sure if the 1080 is the same way, but a lot of 1084s have the horizontal and vertical adjustment controls in seemingly random locations. Some in the front, some in the back. Need 360-degree access to the monitor to make the adjustments.

[SACC-guy]

Aren't there buttons to switch between rgb and composite and luna/chrona?

Some had these buttons on the back, some in front under a door.

Might want to try those...

[walterg74]

Some games are off centre in either or both directions which is obviously down to the programmer of the game. To correctly set up your monitor for your Amiga (any Amiga) you should just have a standard Workbench screen open and make sure your overscan/screenmode settings are both set to default and PAL (or NTSC if you live in those parts and intend to run NTSC games). This is your reference - Workbench default settings...before anyone mucks about with overscan or screen position. Then adjust your monitor settings to match that. Or, open Deluxe paint in 320x256 or 640x256 (again, Workbench overscan and screenmode prefs MUST be default here) and fill the whole screen with a mid grey and then adjust, or draw a white border or something. Or, use a test pattern generator program (some on aminet) or test image. You should leave some gap though to account for overscan, which many games use along with graphics/video utilities.

If you don't have certain controls on your monitor, then they will be on the circuit board somewhere and there will be pots to adjust. Again, all very dangerous working on live equipment and I don't recommend it to be honest. The other knob on the back of the LOPT/transformer will be the screen voltage. No need to touch this, but if you do don't worry just put it back to where it was. Again, CRT monitors / tv's are extremely dangerous with their thousands upon thousands of VOLTS. Don't take any risks, it can easily kill you.

Yep, don't worry I'm familiar with the dangers and won't play around with stuff unless it's risk free I'll just leave it, as it doesn't seem to do anything anyway.

I'm wondering now if whatever caused the piece to break also caused the composite input to stop working...

[walterg74]

Aren't there buttons to switch between rgb and composite and luna/chrona?

Some had these buttons on the back, some in front under a door.

Might want to try those...

Yes, this one has a switch on the front that changes between comp, chroms/luma and rgb. As I stated above, I set this to the correct position, but only the RGB one works.