Naomi Sanwa Monitor problem (Pictures in thread)

[swoon]

Hi,

I have recently bought a Naomi Uni cab with a 29E 31S monitor.
When I bought it I tested the monitor and on first sight, everything was fine.
 
Now I've reassembled the Naomi and I notice that I'm having issues with the width of the monitor.
Vertically everything seems fine.
 
However I cannot get the picture to fit on the screen using the external control board. Even when I set it to the narrowest setting (H. Size), the picture will not fit my tube.
Left and right are too wide for the monitor. When I use this setting, I get bad pincushioning on the horizontal edges as well. Turning the PIN adjustment doesn't  do anything.
 
As soon as I make the image wider with the H. Width, I seem to be able to resolve the pincushion effect, but now the image is far to wide for the monitor to display.
 
Apart from this the image/monitor seems fine.
 
I've read dozens of other monitor threads and it seems that the problem can be caused to the east/west diodes. Where can I find those on the board? I have a service manual but the component names on the schematic are almost unreadable...

Is it something I might be able to fix myself? (I'm confident around electronics, mostly building audio effects and guitar tube amplifiers, completely new to CRT stuff though)

I have some pictures of the screen; The last pic is how the picture seems to be the best I can get it at the moment. (Left / Right image is being cut off though...)









Any advice?

Thanks!

Swoon

[apfelanni]

i purchased maybe around 10 naomis in the last years . 9 of them had sanwa chassis + china tube stuff. 3 of them with defective tubes ( red can down ) , the rest with defective chassis or bad and very bad picture. the only one left with some quality was a toshiba / toshiba combo . i doubt that any approach will make it noticable better . the sad truth is the sanwa crt in sega naomi are the worse thing u can imagine . my last naomi evilbaybuy has the same issues , so i guess its normal .   

some days ago i dismantled a virtua striker 4 , build in 2006 . it has been dumped for a while , so i assume it has been working not more than maybe 4 years . the picture quality is down similar to a universal cabinet from the end eighties. chassis and tube appear to be like new , no burns and 99 % clean . i guess it sucks out of the box  . noone here will pay 30 euro for it .. tomorrow i ll grab a 5 euro tv with toshiba tube as replacement .

either youll have to live with it or dump it in the junk . sorry if thats not much of help dude .
 

[swoon]

Well, that's bad news...

I was hoping maybe replacing the elco's would make a difference?

Is there a replacement monitor that *is* ok that can easily be mounted in a Naomi Universal?

[MonMotha]

Can you grab a picture of the chassis board?  There's often a jumper for "wide/narrow" or similar that you may have knocked loose or plugged back into the wrong thing.  This can affect pincushion, too.

[apfelanni]

i took a photo of my last naomi disaster .. chassis sanwa 29e31s , tube  " goodname " china . my last offer was 20 euro pickup , but the customer refused .

[MonMotha]

I don't see what I'm looking for in those pictures, but that doesn't mean it's not there.

[bytestorm]

Nobody ever solved this problem? ;( I just realised my new cab have the same issue... throwing it out is the only option? Thanks.