Sega-Naomi

I have a New Astro (Toshiba tube) that has a Rodotron 666A chassis.



Two things:



1. The picture is upside down

2. 15khz is sharp in the center, blurry in corners



I cannot seem to find the manual for this monitor. If anyone can assist me in this, that would be great. I am a newbie when it comes to monitor troubleshooting/configuring.

you have 2 sets of coil on the deflection-horizontal and vertical

vertical is a pair of green and yellow

horizontal is a pair of red and blue



you can swap the colours of each individual pair only e.g,

yellow to green/green to yellow

red to blue/blue to red

YOU MUST NEVER SWAP A VERTICAL AND HORIZONTAL WIRE INTO EACH OTHER







have you adjusted the focus on the flyback transformer yet?

Hi grantspain,



Thanks for you reply. I am certainly not a newbie in general arcade-stuff, but I do not know much about monitors at all.



I will swap the deflection wires to correct the picture (i cannot reach them, so I will have to take out the monitor ).



I will post some pictures of the grid pattern soon..



I have not changed focus yet. Main reason is the fact that the picture is sharp in the middle of the screen. I will try and fiddle with it a little, though.

Ok, swapping the deflection wires straightened the picture so it is not upside down anymore. Thank you for that.



I read some stuff about the Rodotron chassis, and it seems that it is inherently bad at 15khz. I am now facing:



right-hand side compression:





Bad convergence in corners (except lower right corner, which is fine):





I modified Focus a little on the Flyback, but to no avail. Any tips, or should I just live with it (or use a different chassis..)?



Thanks

you can't do anything about the side compression and i would guess the convergence issue was there on the old chassis-you will need to either try to adjust the yoke rings(nasty job) or try to use magnetic strips to bring the colours in on the corner(nastier job)

Ok, thanks.. well.. I guess I am going to have to live with it, then. Too much risk for me to be fiddling around with the yoke rings or magnets. Even more now, since you indicate that it is either a nasty or an even nastier job to correct .



With my knowledge of monitors/CRTs I probably would make things worse than they are now..