PC Engine Core Grafx sound issues

[silverwand]

Hello, I have a Core Grafx system and overall I am pleased with its operation. However there is one problem that concerns me. Whenever there is the slightest disturbance of the VGA cable an overwhelming static comes over the speakers and sometimes the screen flickers. At that point, the cable needs to be entirely repositioned for the static to stop. The cable is brand new (the old cable had the same effect). Has anyone else experienced this problem and know what the cause is? Is there a problem with the cable terminal? Also, is this easy or difficult to fix. Thanks in advance.

[Duo_R]

backup here for a second, you said VGA cable. Are you using a RGB to VGA transcoder? Or using RGB hooked up to a monitor that accepts RGB 15hz signal from a VGA plug?

[nat]

I'm sure he's using a standard A/V cable, as a matter of fact, he's probably using a 3rd party one as this is a cut-and-paste of the scenario that plays out when you use a 3rd party (non-NEC) A/V cable with the consoles. Solution: track down a first party NEC-official A/V cable instead.

[silverwand]

Sorry, I was in a rush when I typed this. I am using the standard AV output going into a reciever, then from the reciever to tv/speakers. I had the same problem with my Neo Geo's standard AV output and when I switched to the RGB connections everything was fine. Yes nat, the new cable is a third party production, but I thought the old cable I had was NEC - I guess not. Does the NEC cable have any markings to distingiush it? Both of the cables I have do not have any markings/names on them.

[nat]

Check out the pic in the message here (click to enlarge it).

That is an official NEC A/V cable-- the giveaway is the ribs on the plug.

[silverwand]

That is what the cable that came with the system looks like and was subsequently replaced with a third party cable. However, both cables have the same problem. Should I first try to see if I can get a "new" NEC cable. The original definitely looks used.

[nat]

If both cables did it, it's more likely like the A/V port has a loose connection at the IC board inside. This is actually a common problem.

But if you're gonna replace the cable, you *definitely* want to track down an NEC-branded cable. But I'd check the port connection on the board first.

[silverwand]

Would a loose connection be an easy fix (soldering), or would it be more involved? I'm rather wary of electronics but I'll defintely give it a go if it is something obvious. Isn't a special driver needed to open up the unit?

[nat]

I don't recall offhand what the CoreGrafx requires to open, but it's either a standard gamebit or a security Torx T-15 (or was it T-20?). It's one or the other.

As for the repair, it couldn't be easier. It's a simple solder job. When you look at the board where the port connects, it becomes apparent what solder needs to be reflowed.

[silverwand]

Awesome, thanks for the help nat! Much appreciated.