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deep6

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Hi All, I am currently working on a Golden Tee 99 board, trying to get it to wake up. It's one of those "untested" ebay purchases. When I got the board I did an inspection and comparison of other pics of the pcb and also matched it to my Golden Tee 98 which looks to be a nearly Identical board. The first thing I noticed is one of the caps was missing. There are only 2 caps on this board so I replaced them both (I thought it was an ace in the hole) I also unbent some of the pins on the connectors to make sure nothing was shorted. Anyway I am connecting the board and setting the power as per the manual (about 5.5 VDC) all 4 switches on SW1-Dip all on, and SW2-Dip 1&2 on and 3&4 off.(per GT99 manual) Only Jamma edge connector is attached to the board, no trackball or anything else. And when I turn it on only the yellow "sound status" light blinks. The green "video status" light is dark. Here is a full shot of the board.

1.jpg



Back of the board
3.jpg


I have looked this board up and down and do not see any broken traces or anything visible at all. I have removed and re-seated every socketed chip on the board. (and cleaned its socket with IPA) I also tried swapping these 2 chips from my working GT98 board, and it made no difference:
vidchips.jpg

The reason I swapped those chips is because I know from troubleshooting my GT98 that if they are not plugged into the board you will get no display and no green light and no display. So I know the problem is likely not the chips. I went through and re-flowed the solder on those 2 sockets in case there was a cold solder joint but no luck I see 5v on pin 1 of those 2 chips as well when the board is on. I'm at a loss what to check next. I have also checked voltages from other chips on the board and I am getting power with the right voltages... I am thinking that whatever is wrong it may not be something visible. I cannot find any scratches or problems on the back either, the board appears to be in really good condition. I also connected speakers to the jamma harness to see if the game was playing blind but it is silent even thought the audio light is blinking. And I know my rig is working (I have tons of other jamma boards I can connect that work.) And power must be sufficient, or the GT98 board would not work... (again they look like the same board with different roms) I even went as far as checking prom0-3 with my eprom reader and they all read just fine...

The manual even mentions this problem and gives 2 things I already checked and one cryptic message about U1
Capture.JPG



I have been staring at this board for a half hour and I cannot find U1....

I am at a loss what else to check, any ideas on what components could fail related to video on these boards? Any help greatly appreciated.
 

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Well crap... I found U1, and its this chip right here
u1.jpg

I inspected this really close with a magnifying glass and I see 1 specific section that looks like there could possibly be a disconnected pin (you cannot really see it that well in the picture)
u1_2.JPG


I am not sure quite how to handle that. Its so small I could not get a soldering tip in there, I might try hitting it with a heat gun, but gotta figure out how to keep it from blowing away all the tiny components around it...
 
Yeah, I can’t see the pin so I can’t recommend for sure what to do... but in general:

Cover the whole area in tin foil, then press out the custom chip outline. Remove the tin foil and use a knife to cut out the chip’s outline. Now you have a shield for everything else and a cutout for the chip. Resume heat-gun reflow. If you wanted to be super careful you could buy heat resistant tape and use that to keep the shield down

:thumbup:

But honestly you could also reflow with an iron and drag soldering, if you want to look up that technique. Some flux and some heat would probably do it.

I’m only recommending you try these because this is a golden tee board you can replace for like 40 bucks anyway!

Also 5.5v is too high. Did you mean 5.05v?
 
Thanks for the recommendation. And yes that was a typo, I meant 5.05v. Cheers!
 
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