[SOLVED] Inconsistent/no video output from CoreGrafx unit

[shawn-allison]

I recently purchased PC Engine Coregrafx unit, which is experiencing some odd issues with video output.

Basically what happens is, more often than not, when I power on the system I don't get any picture on the TV.

I'm using an original power supply with the system and can confirm it is technically all working, as I have got the system displaying a very small handful of times and have played games without issue. But invariably I'll come back to start it up again and be treated to a blank screen. Flicking the power on and off obviously doesn't help. I've opened the unit and given the insides a clean as well for all the good it's done.

I've tried multiple TVs and various inputs on those TVs to rule out a bad port. I have tested with both the default composite cable the unit came with and an RGB cable the plugs into the EXT port on the back of the unit. In both cases, the result is still the same.

Any help or opinions would be greatly appreciated.

Thanks very much in advance!

[shawn-allison]

Whether it is helpful or not, here are some photos.

If there is any specific areas I can take a close up photo of, please let me know.


https://dl.dropboxusercontent.com/u/96921/pcengine/IMG_0179.jpg
https://dl.dropboxusercontent.com/u/96921/pcengine/IMG_0180.jpg
https://dl.dropboxusercontent.com/u/96921/pcengine/IMG_0181.jpg
https://dl.dropboxusercontent.com/u/96921/pcengine/IMG_0182.jpg

[Keith Courage]

do you mean there is a blank screen as in it's absolutely black or are you getting a colored screen of sorts?

if the screen is black then there's a good possibility your AV cable is bad.

if you are getting a colored screen than the card slot could need cleaning. Typically putting some rubbing alcohol on a games pins and inserting in a few times takes care of the problem. Also, even after cleaning some systems require the game cartridge to not be inserted all the way to make a good connection. Meaning, once you put the game in pull it out of the card slot slightly before turning the system on.

also, do you have any real games to test on it? Some systems flat-out just won't work well with a turbo everdrive.

[shawn-allison]

So the weird thing is, I have had it working with the Turbo Everdrive no problem previously. Now, when I switch the system on, the screen is just totally blank on the TV. No picture, nothing.

I assumed it was a faulty composite cable to begin with. Just got the RGB SCART cable a day ago. It's brand new, so I doubt that it's bad. Regardless, no picture appears on the TV via composite nor RGB inputs.

I know the system is powering up, as the LED on the Turbo Everdrive lights up and blinks when the system power button is switched on.

Also just tried your cleaning suggestion and loosening the card in the slot a bit, but to no avail.

[Eddiesamma]

There is a good chance it's the connection to the av out din, try wiggling the cable to see if it cuts in/out.

[shawn-allison]

Ideally I'd like to be using the RGB out via the back EXT port vs composite.

I have to figure the issue is outside of the actual video out connectors themselves, since neither composite nor RGB are displaying any output.

Thanks for all the suggestions thus far. Wondering if there is anything on the board somewhere that may be amiss I can check??

[blueraven]

If it just doesn't work at all anymore...

Blown fuse?

Also what RGB cable are you using? Doesn't look familiar

[sirhcman]

If it just doesn't work at all anymore...

Blown fuse?

Also what RGB cable are you using? Doesn't look familiar

Its a cable from fidde_se, I just picked one up myself. Plugs into the EXT connector on TG16/PCE/SGX. Works really well!

[mickcris]

is it a black screen or a yellow/purple/etc. colored screen.  dont see that you answered KC's question.  That would help narrow it down.  If its a black screen, could be an issue with the power port being a bit loose.

[shawn-allison]

Thanks again to everyone that has suggested ideas. After a bunch of trial and error, I believe I figured out the problem, which in turn revealed the issue was something entirely different from what I originally thought.

In terms of composite output, I do believe either the din connector or the cable itself is faulty. The cable does not fit snugly into the port. In fact, it sort of just hangs in the port as opposed to snapping in flush.

With that being said, my intent all along had been to use the RGB cable I purchased that connects via the EXT port. I discovered the reason that too was not working had nothing to do with the console or cable itself and all to do with my setup.

What I'm doing is the following:

PC Engine --> RGB Cable --> gscartsw Scart Switch --> Framemeister

It turns out there is an issue with the gscartsw switch properly receiving the video signal through the RGB cable. If I bypass the switch entirely, and just plug the cable directly into the Framemeister, I get a nice clear picture without issue.

After contacting fidde_se, who makes the cable, I learned it is a known issue and he is able to make an adjustment to my cable to make it work with the switch.

Hopefully my experience can be a good reference point for anyone planning to go down a similar route in future.

Thanks again for everyone's insight on this matter.

[mickcris]

I assume you have an older switch that needed voltage on pin 16 and it is not connected to the scart plug on your cable.

[shawn-allison]

@mickcris: I don't know the specifics, but I was told the solution involves changing an amp in the cable. I'm not an electronics expert by any means, so I'm not sure if this relates to what you mention about the voltage on pin 16.