aftar a fubar gorf only plays b@w need help

discgolfer72

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during my gorf brain transplant i droped a wire and it hit the moitor frame frying the monitor and it seems doing somthing to the game board

i have tried 3 known working monitors and all i can get to display is a black and white immage game seems to play fine other than no color
i can get some color but that is by cranking up the color drive pots on my neckboard

(ps posting this here because its not a monitor ishue since i have used 3 known good monitors)

where should i start is there somthingthat controls the color on the board set
here is a pic of my display
DSC03764.jpg
 
Looks like black and green to me, indicating no red or blue signal, unless you have the green cranked way up. If it truly is black and white, then all three colors may be on at once.

Do a voltage check at the video input connector to see if you get about 2.5vdc at each color input. That will tell you what colors you're getting and what you're not.

You could check Q8 and U15 on the CPU board for damage, as they output the main Video signal, although the PDF scans on ArcArc aren't good enough for me to find the actual RGB signals...
 
cool thanks guys man im pissed at myself oh well
im rearangeing the shop now so i can have more room and less clutter (arggg its driving me nuts )
once i get the shop all put togather ill be digging back into gorf so ill get back with you all once i do

as for the green i have the green drive cranked up so i could see the game since i was wireing up the cp and need to see what my inputs were doing

ps how long was the site just down for
 
Looks like black and green to me, indicating no red or blue signal, unless you have the green cranked way up. If it truly is black and white, then all three colors may be on at once.

Do a voltage check at the video input connector to see if you get about 2.5vdc at each color input. That will tell you what colors you're getting and what you're not.

You could check Q8 and U15 on the CPU board for damage, as they output the main Video signal, although the PDF scans on ArcArc aren't good enough for me to find the actual RGB signals...


do i put my ground probe on the ground pin on the molex or somewhere els
 
god damn harbor freight crap my old bp meter sot shit on me so i bpught one form harbor freight dam thing wnt even pick up voltage on bats arggggggggg it will dect amps but will not do ac or dc voltages

shred
problem is i dont have a second rgb board been trolling ebay with no luck there is only 2 gorf boardsets listed one guy wants 50 $ for a partial set and another guy has an untested set and neiother come with the rgb board
 
You should not need to get the full board set for this little board. It is the one little board with the two cardboard tubes that mounts to the side of the cab... They come up for sale pretty often and sell for under 30.00. I think are the same in wizard of wor. they look like this:
http://www.classicarcaderesource.com/GorfRGBpcb.jpg
Try and find someone close to you thats has a gorf and let them test yours or let you borrow thiers. If not put a want add in the wanted section here for one.

Also read this link.
http://www.biltronix.com/gorf.html
He seems to have had a close to the same problem. I would check those resistors he talkes about.

Dave
 
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well got scrwed by harbor freight they would only give me stor credit on the meter i bought oh well im shure ill find some kind of crap i need there eventualy

on a up note i hit up the trusty old pawn shop and snagged a fluke for 39.99(also got them to do it tax free )
its an older model but at least its auto sensing (funny thing is it is one of the meters given to students at the auto tech school i went to in chi town /but when i went there they were giving blue points lol)
DSC03777.jpg




tested my voltages at the rgb molex at the monitor and getting 3.06-3.14 on each pin
so what next

ill look at that link about the resitors and se what i get on them here in a bit
 
shred after reading the link you posted it seems he was not getting red at all at the monitor molex and also not at the rgb board
after testing voltages it seems that i do get all thre colors but it may be that they are always on an at full throttle as 3.14 v seems a little high to me
 
That fluke is a good meter and the price was good too. Blue point is snap on tools lower line. I bet their meters are made by fluke too.
 
lol yea i loved the blue point i got from uti when i registerd im pissed the display craped out on me
i was going to get the blue point they had at the pawn shop but it was 69$ and was not auto sensing and when i saw the fluke had the uti stamp on it i was like ill take it lol



back to the reapair just got off the phone with the guy that suplies me my empty cabs for mame /multi cabs and he says he has a rgb board for me so im going to shoot down there tonnight and pray to the arcade gods that the rgb board is my problem if not guess ill snagg that gorf boardset on feepay and hope it either works or has the right parts i need to fix mine

(crossing my fingers he also has a gorf bezl if so my gorf will be done excpt the holes in the cp and side art )
 
thanks much all for all the help and talking me down from my pissed at myself mood lol

it was indeed the rgb board that took a dump form me shorting the lighting wire on the monitor frame
picked up a rgb board from my good buddy and bam we have gorf in color
i still need to make some adjustments but its looking good so far (kinda glad i took out that monitor it was in need of a cap kit and had burn from like 3 diffrent games this one has a little burn but has a way nicer picture )
DSC03785.jpg

DSC03786.jpg


now on to the cab repaint and new side art and to track down a bezl

ps anyone got a bezl lol
 
Yea I figured it was the rgb board. I still think it was the tba530 chip.. I would really like to see that chip replaced to see if that was the issue on yours... I would really like to pick some dead RGB boards up in the future and try and fix them, there does not seem to be much too them. The 270 ns delay on them is the only thing I am not sure of.
Dave
 
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I've always been tempted to short over the delay lines and see how the image is actually affected.

With a 15.7kHz Hysnc, and assuming 320x240 resolution, you'd get a 5.5-6Mhz bit frequency, so that delay line is at most 1-2 pixels... At worst, I'd expect to see something that looks like a uniformly misconverged image.

I'll have to dig out a gorf and try that sometime...
 
Though you don't need the help now, but for future reference, I believe the Astrocade based boardsets (Gorf, others that use the cage) output composite with component video, and that interface board converts it to pure RGB.

This means that you can take modern TV sets that accept component (aka ColorStream on Toshiba's) and feed it a Y, Y-R, Y-B component sigal and see if the board is outputting the correct video before it's the converter board.

In fact, I think the Y line is actually a full composite video signal (not just green+sync) and can therefore be used to feed a composite input too, but I've not tried that.

Yep.. you can connect Gorf directly to almost any TV set if you want--with the native output.
 
Though you don't need the help now, but for future reference, I believe the Astrocade based boardsets (Gorf, others that use the cage) output composite with component video, and that interface board converts it to pure RGB.

This means that you can take modern TV sets that accept component (aka ColorStream on Toshiba's) and feed it a Y, Y-R, Y-B component sigal and see if the board is outputting the correct video before it's the converter board.

In fact, I think the Y line is actually a full composite video signal (not just green+sync) and can therefore be used to feed a composite input too, but I've not tried that.

Yep.. you can connect Gorf directly to almost any TV set if you want--with the native output.

Interesting, I did not know that... I always wondered why an rgb board but never went deep into it...


Dave
 
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