Another Gorf Problem

kestep

New member
Joined
Aug 3, 2012
Messages
39
Reaction score
0
Location
Zebulon, North Carolina
I acquired a Gorf after a long time without one.

The monitor works and the cab, marquees, and control panel are in pretty good condition.

However, the games does not work. It has the original linear supply.

I checked the voltages at the card rack connector.

The 12V line was high and the +5V and -5V lines were low.

I adjusted the power supply:
12V Line: Was 13.8V, Adjusted to 12.1
+5V Line: Was 4.7V, Adjusted to 5.1V
-5V Line: Was -4.8V, Adjusted to -5.1V

The game still did not boot.

I connected a switching supply in its place.

The game still did not boot.

I have an assortment of untested boards (2 RAM Cards, 1 Pattern Board, 1 CPU Board, 1 ROM Board).

I swapped the cards in one at a time and tried to start the game. After swapping the ROM board in, I get some activity as shown in the pictures, linked below, but the system still won't boot.

I'm looking for some guidance on what to check next. I suspect the Game Board, and have no spare to use to test.

I'd like to try to repair it myself, but won't rule out sending the boards for repair.

Pics:

This is with the Self Test Switch on. The rank lights cycle through in order.
http://carolinapcpros.com/wsarcade/gorfprob1.jpg

This is with the Self Test Switch off.
http://carolinapcpros.com/wsarcade/gorfprob2.jpg

I can upload video of the screen, as the blocks are moving, not static.

Thanks for anyone who can give me a push in the right direction!
 
Check the connectors for sure and clean them as best you can. Pull all the cards from the cage and look down in the bottom with a flashlight to make sure there is nothing in the slots and that the edge connectors of the cards are clean as well. Try swapping the cards around in the cage (position) or even use a different cage if you have one and see if you get different results. It will be tough if you don't have cards you know are good.
 
Swapped card positions... no change.

Also previously swapped my spare card cage... no change.

Any other ideas?

Looks like the cards are headed out for repair. Once I get a working set, I'll swap in my second second set and see what works and what doesn't.
 
I might have a similar problem...

Who fixes the boards or can test them??

I might have something similar going on. I can see some of the graphics on the screen like th e stars and the force field arc....but the rest just looks scrambled...

I'm also having an audio problem and I can't figure out where to get parts for the audio board. If you know anyone who has an extra board to sell or knows where to find parts, I would be a happy camper.

Thx,
jot
 
That may be a problem with your pattern board. The most common problem with Gorfs are the 4027 rams on the ram cards. You said you swapped in some known good ones right?

I have parts, which parts do you need for the audio board? You can replace the two transistors with TIP31C. If there are any discolored resistors you should replace them. Either way you should ohm out all the resistors to make sure they are in tolerance. There are a couple on there that get burned, up those to 1/2 watt.
 
Back
Top Bottom