Another Commodore1084s-d1 monitor sync problems with pce.

[bigsanta]

There's a few topics on here ,about these bloody monitors,so here's another!

Yesterday i managed to get myself an commodore amiga 1084s-D1 monitor PAL version,the one with the 9pin d-sub socket,and i have wired up a d-sub plug with the R-G-B ,composite video to the sync and ground to the d-subs 2 grounds and all i've got is a picture that can't sync.

So i tried the resistor fix on the sync/composite video line,and the closest to a stable picture i get ,is with 400ohms in series,and this is with dynastic hero on the title screen(but the colours are not correct somehow ),stick in shinobi with it's moving title screen and the sync problems come back,any moving on screen action and the monitors goes haywire again,sometimes all the colours except red will go,then everything but green will go,i've also tried with a pot,but this was 50k and trying to fine tune this was a right bugger,and when i did get a stable picture again with dynastic hero ,this just went off sync again when i used anything else with movement.

After 5 hours ,this is what i've tried and failed with,combinations of all;

Put an amp on the consoles composite video line

Put an amp on the consoles comp sync line

Added 75 ohm resistors on the R-G-B lines

Various resistors on the comp sync/video line with and without an amp.


It seems a lot of people have had problems with these monitors,so i'm just wondering if i should just get rid of this model ,along with the head aches and get the normal 1084/s.

fraser

[bigsanta]

http://www.atariage.com/forums/lofiversion/index.php/t91644.html

I've been trying to get a 1084DS to work with composite sync going in on pin 7 and had no luck. I googled around and found this thread talking about how some 1084's just don't take composite sync. I tried feeding it to pin 9, both pin 7 and 9, but nothing worked.

So I took a look at the schematics and did some experimenting. I finally got it to work by doing a slight mod to my monitor.

I put a jumper across pins 6 and 10 on the chip labeled I202 (a 74L506). After that, I put composite sync to both pins 7 and 9 on the 9 pin connector. That worked very well. Here's a picture of the jumper I made.

[NFG]

I occasionally read that there's a problem with these monitors, but I never had any trouble with any of the ones I had, so I never looked into it.  Nice to see there's a fix, thanks for the link.

[bigsanta]

http://staff.washington.edu/rrcc/uwweb/1084S-D/BLOCK.gif 

http://staff.washington.edu/rrcc/uwweb/1084S-D/1084S-D.gif

[bigsanta]

One more thing to add,something which i didn't know,but others might,you don't need the RGB amp when connecting a pc engine to this model monitor,and even my mega drive is fine without any resistors on the RGB lines.

What a picture this screen gives,even more beautiful when you calibrate the white and black levels !!