Nba jam tournament edition

PacAttack13

New member
Joined
Oct 2, 2010
Messages
836
Reaction score
3
Location
Omaha, Nebraska
For some reason my NBA JAM tournament edition will go thru its rom check and everything checks fine and it will get to the initial screen and then keep resetting itself. What could be the possible problem?
 
im thinking its just a loose connection as I turned the game back on and theres neck glow but all i got was a black screen....so I messed around with the wires and the game came back on....ill just turn the game off and make sure the edge connecter is on the board correctly.....and go from there....i know the power supply is putting out the power and the led light is lit up....dont know what else it could be...any help would greatly be appreciated....thanks :)
 
prolly a short in one of your wires, are there a lot of patches/electrical tape ect. in the wires your messing with? best thing to have is a voltmeter, through trial and error you'll find which wire/wires is giving you issues, check the most important ones first (12v/5v/ground).

If you have a meter and it has a continuity check setting it makes life a lot easier and you don't have to have the machine on to find a break in a wire.
 
power supply voltage could be extremely high or low too.

try to aim for 5.2V. if it's an old Peter Chou screw terminal unit it may additionally need some help. lol

not everyone can have a cool light bulb tool like I do though..
 
power supply voltage could be extremely high or low too.

try to aim for 5.2V. if it's an old Peter Chou screw terminal unit it may additionally need some help. lol

not everyone can have a cool light bulb tool like I do though..

what's that tool look like? :D
 
I took one of the lamp fixtures from one of those redemption pushbuttons, the kind that takes a #555 bulb, added 2 wires to it and crimped male molex pins to them that plug into the 9 pin power supply connector. stick one pin in the +5, the other in the ground, now you've put a 5 volt load on the power supply so it doesn't burn out.

with the power supply powered off, turn the +5 adjustment knob back and forth a few times to its extremities, then using your best judgment put it back in the centered position. this process is called "wiping" the pot; in some power supplies over time, you'll probably go to check them and find them running at some absurdly high or low voltage, and you'll more than likely notice this in games that often times will randomly lock up, this is because the potentiometer has formed oxidation on its contact surface, turning the wiper inside the pot all along the contact surface will self clean it, kind of like braking to get the rust off of a disc brake.

with the lamp tool plugged in instead of your JAMMA connector or game board, you can stick your meter probes in the opposite end of the 9 pin connector on the +5 and ground pins (any will work) and test your voltage. ideally I try turning the +5 knob on power supply down to see what its floor voltage is... you never want this to be too high, like a 5.0-5.1 or greater, you want it to actually go down to 4.85~, then I go the opposite way to check the ceiling, you don't want a power supply that struggles to hit 5.3 or greater, which means you probably have faulty caps inside.

if the power supply passes these tests, then it should be fine for awhile longer. if it's really old, or one of those goofy Peter Chou units, periodically check it like every 2-4 weeks. also ensure that the fan is operating properly, if it's knocking or making buzzing sounds then the bearings are shot and it's going to fail soon, or if it's completely ceased, it's time to punt on it. you can replace these, they just use the same kind of 80mm fans that go in a computer case, if you have an abundance of these laying around in your shitpile they make good donors.

while you're at it, you can check the +12 and -5 voltage as well. these voltages are unregulated, meaning you're not going to have perfect 12.00 and -5.00 voltages, the +12 oftentimes will run higher, like a 12.5-13.5, and the -5 will run around -4.75 to -5.05 (maybe) ... I kinda came up with these numbers based on tolerances. they operate relative to what your +5 is set at. if you find them too out of whack for what +5 you're throwing out, then your switching power supply is operating inefficiently, likewise due to failing electronics, and therefore should be replaced.

that's basically my power supply 101, I do that on all our video and redemption games in my family's arcade. sometimes you can get some extra mileage out of a power supply, and sometimes you can't. if it's a unit that's had a ceased fan for a long time, or the damn thing is just way too old and has been used way too much, the electronics inside will start to fail and it's time to just replace it. some power supplies to my knowledge don't even have replacement parts available for them, and for the price you pay and the time you waste trying to rebuild a switching power supply, you could've just had a new one. the only exception to the rule with power supplies is if it's an old classic game with a linear style power supply board.

that's it. also my lamp tool will work with screw terminal power supplies as well, just get out the alligator clips, hook them to the molex pins and sandwich the lug screw in the clip on the other side.
 
very nice, i'll have to see about putting something like that together.
 
Back
Top Bottom