View Full Version : JPAC 'Sync OK' LED

17th January 2008, 07:26 PM
Hey guys,

I have been getting dominated by syncing issues since getting my AVGA and PS2 adaptors, with no idea how to iron it out. I think i may have spotted an inconsistency which leads me believe my JPAC may be faulty (and because the monitor is fine with JAMMA boards). The details of my problems with Elvis's assistance is in this thread http://www.aussiearcade.com/showthread.php?t=11311

The SYNC OK LED should illuminate when the frequency is 'OK' for the monitor as I understand. IE: with 15KHZ jumper ON, the JPAC waits until the signal is 15KHZ, then lights the LED and lets it through.

Well mine is ALWAYS ON. When the PC is in standy, SYNC OK is ON. When I have the jumper on 15 or 24 or 31 the SYNC OK stays one. It is my understanding that if I have the Jumper on 31, and am sending it a 15 signal...sync OK should NOT be illuminated and it should not be sending it.

What do you guys think? Am I clutching at straws or could this signify a fault in my JPAC?

Arcade King
17th January 2008, 07:51 PM
I have my jumpers set to 15/31 and when i turn pc on i get sync ok straight up with arcade VGA. When i was trying Soft 15khz i would get the split screen (thats 31k/2) and sync was ok then as well.

17th January 2008, 08:24 PM
Okay, so what if you set it to jumper 31KHz, and run your arcadeVGA.

To me that is doing the following:

"Hey JPAC my monitor is 31KHz, have a 15KHz signal"

So the SYNC OK light shouldnt light up should it? Mine does, no matter what combination.

Arcade King
17th January 2008, 08:30 PM
Sounds like you have a issue with your Jpac then or the connection to your monitor.
What sync is used IE 15 or 31k depends on what is being outputted by what ever is connected to the Jpac EG Arcade VGA. even if it was outputting 31k the Jpac splits the signal so what you see is a split screen.

17th January 2008, 08:37 PM
yeah I realise this. I emailed Andy and he says it is operating incorrectly.

Strangely enough, I got my old card (GeForce FX5200 with Soft 15KHz) and the JPAC operated as i expected (sync light was dependent upon signal ie: off during boot, on during windows) and the CAB RAN PERFECT.

I have told Andy this and hope he can come up with an explanation. Seems the JPAC is acting up when used with the AVGA...but they are meant to go together like Chicken and Avocado at Subway.

Arcade King
17th January 2008, 08:38 PM
Sure its not a faulty Arcade VGA then?

17th January 2008, 08:46 PM
yeah I guess thats what its pointing to. Waiting to hear back from Andy. I feel bad cause I've been asking him so many questions, and you guys as well. Hate that feeling where 95% of my posts here are asking for help and only 5% are solving someone elses problems.

Hopefully a resolution will be reached soon :)