GORF White Screen, No video

Phetishboy

Well-known member
Joined
Dec 12, 2006
Messages
47,929
Reaction score
9,392
Location
Avon, Minnesota
I was redoing some of the poorly twisted connections to the 28 pin connector that plugs into my GORF board-stack. I re-twisted the wires, one at a time, added solder and shrink tubing. Went to fire it up, I get a white screen. Audio is there, attract mode works, game coins up and plays. What gives? I rechecked the pinout and everything seems to be in the right places. Like I said, I did them one at a time.
 
Is there a color-coded visual guide for how the wiring should be hooked up? This has to be a video problem. I looked at the pin-out, and everything seems to be where it's supposed to be. Game plays blind now. Worked fine before I tried to 'fix' the edge connector. Help.
 
sounds like no/improper video signal getting to the monitor. I'd check connections for continuity. Actually I think with no signal you get a black screen unless we are talking a classic nintendo like DK. I'd check to make sure it's wired correctly.
 
Is there a color-coded visual guide for how the wiring should be hooked up? This has to be a video problem. I looked at the pin-out, and everything seems to be where it's supposed to be. Game plays blind now. Worked fine before I tried to 'fix' the edge connector. Help.

Hey Phet,
I'll be inside my Gorf today, in the shop. If no one replies by this afternoon....I'll note my wire colors and reply.

Edward
 
Hey Phet,
I'll be inside my Gorf today, in the shop. If no one replies by this afternoon....I'll note my wire colors and reply.

Edward

Awesome Ed. I doubt anyone else will. I owe you a 6 pack. Can you send alcohol through the mail these days?
 
Alcohol

Awesome Ed. I doubt anyone else will. I owe you a 6 pack. Can you send alcohol through the mail these days?

I believe you still can.

Ed, I will be down today to pick up the boardset that is giving you a reason to be in your Gorf. :) I will drag my feet as much as possible to give you plenty of time..
 
Here's what my current clusterfuck looks like:

P1230386.jpg

P1230384.jpg


And PW, you have a typo in your sig? How is that even possible?
 
Darn it! I've had that for at least 3 weeks and it's finally been caught.....

Back onto Gorf, pull your boards out of the cage and reseat them, making sure the boards aren't touching each other. My issue seemed to be a heat-sink touching another board.
 
Damn Phet,
I would have cut all those splices out and crimped new pins on.
Here the pin colors...

J1
1-empty
2-empty
3-empty
4-empty
5-empty
6-empty
7-BU/YL
8-RD
9-BR/YL
10-YL/GN
11-OR
12-BR
13-empty
14-BR/WH
15-BR/BK
16-WH/YL
17-YL/BK
18-GN/BK
19-RD/YL
20-OR/RD
21-RD/WH

J2
1-GN/RD
2-YL/GN
3-BK/GN
4-empty
5-BU/YL
6-RD
7-BR/WH
8-BK/WH
9-RD/YL
10-GN/YL
11-Lt BU/WH
12-OR
13-WH/GN
14-RD/BK
15-empty
16-empty
17-YL
18-empty
19-Wh/RD
20-BR/YL
21-RD/WH
22-empty
23-BU/YL
24-WH
25-RD/YL
26-WH
27-RD
28-WH

The video signal runs through connector J2 pins 17 and pins 19-21 and 23-28.

Edward
 
Last edited:
Damn Phet,
I would have cut all those splices out and crimped new pins on.

I will be. I just didn't have those small pins in my parts drawer. That big yellow wire carries the video then? It's the one supposed to be at pin 17, next to the key?
 
I will be. I just didn't have those small pins in my parts drawer. That big yellow wire carries the video then? It's the one supposed to be at pin 17, next to the key?

Pin 17 is a larger gauge yellow wire. The video signal runs through pins 17/19/20/21/23/24/25/26/27/28.

From the motherboard, the signal then runs to a small board called a "RGB Board"......it then leaver this board and heads to the monitor. These RGB Boards can be a problem.

Edward
 
Pin 17 is a larger gauge yellow wire. The video signal runs through pins 17/19/20/21/23/24/25/26/27/28.

From the motherboard, the signal then runs to a small board called a "RGB Board"......it then leaver this board and heads to the monitor. These RGB Boards can be a problem.

Edward

Well I have that yellow wire in the right place, and that was my only concern. Can these RGB boards be tested/ repaired/ replaced?
 
Well I have that yellow wire in the right place, and that was my only concern. Can these RGB boards be tested/ repaired/ replaced?

I'm only aware of three games Midway used these RGB boards in.....Gorf, Wizard Of Wor, and Robby Roto. It'd be nice if someone around you had a game you could test it in. There isn't much to them. I've had the oddball pre-amp chip bad......and those clunky delays crack loose.

Edward
 
The only thing that goes bad on the RGB board usually is the TBA530 chip. Actually they fail pretty commonly. I have these in stock, just got some in last week.
 
The only thing that goes bad on the RGB board usually is the TBA530 chip. Actually they fail pretty commonly. I have these in stock, just got some in last week.


Looks like I'll need to try one. Other than crimping on new pins (which I will do when my Bob Roberts order arrives), all the wires are in the right places and making contact to their corresponding pins. I'm stumped. I get a white screen, but I can see colored movement around the very edges. I tried to mess with the pots, but I still get no image.
 
Oh, one more thing. I realized before I posted this thread that I had put the large yellow wire on pin 18 by mistake the first time, and got a blank screen. Then I removed it and put it on pin 17 where it belongs, and got the white screen. Could having it on the wrong pin cause that chip to fail?
 
Edge connectors re-pinned and/or replaced, RGB board tested, IO board tested. I am still getting a white screen, and the game plays blind. This is a rebuilt G07. Backed up a newer monitor to test and got nothing on the screen. I was later informed that Gorf doesn't like newer monitors (WG 7200), so I still need to test with an older monitor to rule the G07 in the machine out as the culprit. Here's the screen I am getting:

photo38.jpg
 
Back
Top Bottom