NBA Jam test switch

tinsley

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I have a NBA Jam cab that doesn't have a test switch on it. When I use the dip switch to put it in test mode I keep getting the screen saying that the dip is set to be in test mode, hit any button to continue. When I hit a button, it flashes to test diag screen and fight back to the screen telling me to hit any button to continue. I can not access any settings because it keeps going back to that screen. Any ideas?
 
wire in a test switch...

Sounds like something is wrong on the pcb.. Maybe bad battery?

It should not exit test until you tell it to exit and then it will complain the dipswitch is set on test..
 
I just put in a new CMOS battery. Maybe it's the wrong one? Anyone know which battery this pcb uses? I used a CR2325....
 
wire in a momentary switch for the test button (just like mr bill said) then tell us what happens :D
 
Thats the right battery.
A failing power supply or voltages that are off will might be causing your issues.
A bad crystal was the cause of the last NBA jam I dealt with that use to reset back into test mode.
 
Very finicky. I just repaired my NBA Jam. It would not boot up adn would go on and off. I took all the roms out and put them back in, nice and slow. Re-seating them. This took care of the problem. MAke sure your JAMMA connector is good and clean too. MAke sure your power supply is putting outr EXACTLY 5.1v

Hope it helps!
 
Checked voltages. If they are at 5.1V the board will not boot. Adjusted until the board, same issue. I can not figure this out... The jamma harness does not have the wiring/pins for the service switch so until I get some parts I can't do the switch install to test...
 
oh, no, i checked at the power supply. where would i check on the board?

you put the red probe on the +5 pin on the board. with the jamma harness connected there's a little exposed area you can touch it. Black probe to ground.

Midway boards are crazy. sometimes re-seating your roms will fix a lot of issues. sometimes you have to do it a few times.
 
yeah, i was dumb. i figured that out. ok, that WAS at 4.9, now at 5.1V. still does the same thing.... pictures to follow...
 
yeah, i was dumb. i figured that out. ok, that WAS at 4.9, now at 5.1V. still does the same thing.... pictures to follow...

nah not dumb. I think with midway boards it is especially important to check voltages at the board because it uses a separate sound pcb that will take some of the power and leave your game pcb with less.

you might want to try tweaking the voltages a little, maybe 5.2, maybe try less, midway boards are really funny sometimes they just need a little increase or decrease in power.

re-seat your roms again, trust me it helps
 
i will pull the board and give that a try... i haven't worked on games in a while, so i gotta try to find my tool to pull the chips...
 
this is all i can get.... when i hit any button, it flashes to the service screen and right back to this screen every time...
 

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this is all i can get.... when i hit any button, it flashes to the service screen and right back to this screen every time...

ok I know your jamma harness is missing the crimp pin for test but just take a wire and touch the Test pin on your pcb and a ground to make the connection so it's like pressing the test button.
 
ok, wired switch first to the service switch.... grrr, wrong location, as that just added credits (as it should, i was rushing...). threw switch onto correct locations and voila, it works.. now i can access the diag and so on...thanks for all the help, everything seems to be fine. while i had the board out i noticed the battery wasn't being held in very tightly, so i fixed that up and solved the problem and my damn cmos error... nice...
 
ok, wired switch first to the service switch.... grrr, wrong location, as that just added credits (as it should, i was rushing...). threw switch onto correct locations and voila, it works.. now i can access the diag and so on...thanks for all the help, everything seems to be fine. while i had the board out i noticed the battery wasn't being held in very tightly, so i fixed that up and solved the problem and my damn cmos error... nice...

i figured the lack of switch was the issue, glad you got it fixed.
 
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