Vertical Hold Problems on Nanao

[Tron]

Hi

I have a Nanao 26" monitor and I'm having real problems getting a stable vertical hold.

I have a Geforce2 card driving the show and I've run Hsync and Vsync through an XOR gate to create composite sync (I read it on a web page somewhere). I've also tried straight hsync.

I'm running advancemame on windows 2k, but, I have also tried advancemame on dos and arcadeos on dos.

I've played with the monitor controls and had some caps replaced on the board.

I've also played with my modeline a lot (mainly the YT value).

The result is that sometimes I get a stable image, but, mostly is starts a very slow roll after 30 seconds or so one line at a time. Also the image is often at a different vertical pos when I run mame.

I have not seen it myself, but, I have beed told the setup works fine with a real arcade board.

My next step is to buy a j-pac unless anyone else has any ideas?

[Tron]

More...

Actually if anyone has a working nanao 26", would you please post the modelines you are using.

If anyone has a nanao manual that would be good too, especially the following specs:

H active
H front
H sync
H back

V active
V front
V sync
V back



Also, what do people think of the various methods for creating comp sync?

1) Use Hsync only

2) Twist hsync and vsync together

3) Runs hsync and vsync through and XOR gate

4) Build a converter circuit as found on various www sites

5) Give up and buy a j-pac


cheers
Andrew (aka Tron)

[dabone]

Running hsync only will only give you hsync. You can try to get it to stop rolling with the knob but it will never be stable.

Just tie the lines together and give it a shot.
Works more times than not.


Later,
dabone

[Tron]

Thanks dabone, but, I have already tried that with no luck.

Good news though...

I bought a J-PAC today and it solved the sync problem out of the box!!
Great product. It even has diagnostic LEDs on the board to tell you if SYNC is OK.