Gorf display issue

skramarck

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Hi,

I am a relative newbie who just picked up a pseudo functional Gorf for restoration. The game will play, but the display is wonky (see attachment). Based on the photo, am I looking at an internal adjustment (such as a horizontal size coil), a cap kit issue (something that will get done eventually anyway) or something more devious such as one of the circuit boards. Any help is appreciated. I'd like to get it somewhat operational for the kids to play before I take it offline for repair.

On a slightly related note, anyone know where to get the bit that allows you to take the joystick apart? I'd like to replace the burnt out light bulbs

thanks again!

Steve
 

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looks likely to be a monitor adjustment. as for the joystick you probably just need a set of security bits. Can't recall if that stick uses the hex or torx with the center hole in the bit.
 
Just an update....tried every adjustment possible and checked
The sync with oscilloscope . Everything checks out fine but problem persists.

Going to try cap kit and cross fingers.....anyone else have any inkling
As to what might be wrong?

Thanks again!
 
Bumping this with an update as Gorf is still not resurrected. Here is what has been done. I'm not sure what to try next....Any advice is appreciated. I believe the monitor is a WG 4616. I'm a technical newbie, but I have access to an electrical engineer who might be able to help if I were guided in the right direction. The only monitors that I have access to for testing are the ones in my Nintendo Punch Out and I don't think that they are the same model as Gorf.

Here is what I've done since the photo was taken.

* Checked all wires for corrosion, breaks, etc. Checked all connections...all appear to be solid.

* Re-capped the monitor
* Replaced the TBA 530 on the RGB board.
* Sent RGB board for testing on a known working machine (it checked out fine)
* Sent game boards for testing....all checked out fine.

At this point, do I assume the monitor is bad or are there things I am overlooking. I would love to get this game up and running.....thanks for any assistance that anyone can provide?
 
That sure looks like a board issue to me; my first guess would be the pattern board, either RAM board would also be suspect.

Are you able to play the game "blind", GORF's game play collision detection was implemented a little different than others, so common RAM failures will detect as collisions; that's sometimes helpful to know when you're starting with an unknown machine.

Was your complete board cage tested, or were the boards taken out and put in another cage? While it sounds like a long shot, I've had ROM labels fall off and become wedged in the edge connectors in the base of the cage while testing boards. Those labels aren't too good a conductor :)
 
I believe the monitor is a WG 4616.

Assuming that the game board is OK, and the problem really lies in the monitor...

The 4600 monitors have two cards that plug in the back. These things are *notorious* for cold solder joints, and assorted other flakeyness. You need to resolder the connectors on both the cards, and the main chassis, and be sure the header pins are clean. Also, don't miss the sync adjustment pot on one of the cards - it's square and silver, and labeled L351 (IIRC).

Sync issues on 4600 monitors aren't that uncommon either. And I've seen other parts on those plug in cards fail as well. If possible, swap the cards from another monitor.

-Ian
 
The boards and cage were successfully tested, so they are fine. It played blind when I got it, but I sent the boards out for testing just to be sure and they tested A-OK.

I will definitely look at those solder points on the monitor boards and look for that sync adjustment. We might have missed that one when my friend and I looked at the machine
 
i have seen that problem before in one of the vertical cards that attatch to the 4600 chassis.
its most likely one of those.
usually, when a ram board in the cage has probs, it shows red lines, streaking and your ship will explode at random..when u r playing.
 
Updating for anyone who is interested. Got the Gorf monitor operational. Previous owner had jumpered the sync connections on the connector from game board to monitor. With a little tweaking, I have a solid screen now.

The remaining problem is that the blue color on the first battle is very dull and dark. I am unable to adjust that. I will be checking the few parts on the monitor related to blue and will also swap another rgb board in when I receive it Friday.....can anyone think of any other areas that could impact blue level on Gorf with a WG 4600?

This game is very close to being operational again.....can't wait!
 
Updating for anyone who is interested. Got the Gorf monitor operational. Previous owner had jumpered the sync connections on the connector from game board to monitor. With a little tweaking, I have a solid screen now.

The remaining problem is that the blue color on the first battle is very dull and dark. I am unable to adjust that. I will be checking the few parts on the monitor related to blue and will also swap another rgb board in when I receive it Friday.....can anyone think of any other areas that could impact blue level on Gorf with a WG 4600?

This game is very close to being operational again.....can't wait!

IIRC, that RGB board has a few parts on there than can fail. I'd check them... but since you're getting a replacement already, then I guess that's a moot point.

FWIW, don't just junk the old board, I'm sure there are people that would be interested in it.
 
Just a final follow up in case anyone else may benefit from my ordeal with Gorf. Monitor is decent now that sync and oscillation adjustment have been tweaked (For what it's worth, the sync wire that was jumpered, then removed, has now been put back in......I think the wire wasn't the issue there, rather it had some corrosion which was cleaned when removed).

The missing blue was definitely from the RGB. I have a different RGB board in there and it is working (although I have the Gorf version with the duller colors...oh well). Working on putting a new TBA 530 chip in the missing blue card to see if it works again.

Other issues stumbled across in this project. Joystick lighting was out, repaired by replacing the Q7 transistor in the rank light board (Tip 120 I believe) and grabbing some 1137 bulbs from the auto store.

Sound issues rectified by reflowing the audio board.

The last step (for now) for me is to put new optical sensors in the joystick assembly as I have no up/down motion for now. I hope to have that repaired tonight.

thanks to all that helped in troubleshooting this and testing various boards for me...it was a big help and I've learned a lot on the way..... LONG LIVE GORF!
 

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