NBA jam stuck in test mode

pipcade

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My NBA jam is stuck in test mode. It says "dipswitch test select (uj2 = 8) closed."

No matter what I do to the dipswitches it always says this. Is my dipswitch busted? Is there a way to bypass this?
 
Generally the game goes into test mode when the test switch is enabled.
The test switch is "not" on the game board itself.
The test switch usually is a test switch button towards the front of the game towards the coin door.
Do you have a test switch installed on the game?
 
Generally the game goes into test mode when the test switch is enabled.
The test switch is "not" on the game board itself.
The test switch usually is a test switch button towards the front of the game towards the coin door.
Do you have a test switch installed on the game?

correct if there is no test switch installed it will just stay in loop.
 
Guess I should have specified the cab does have a test switch and it says a diff msg when I flip it. This is def not indicating the test switch.
 
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Guess I should have specified the cab does have a test switch Ns says a diff msg when I flip it. This is def not indicating the test switch.

the dip switch on the board could be bad or have some corrosion (flip it on and off a few times while powered off then try it).

is your test switch on the cab good? (gotta ask).

i'm guessing there's corrosion or an issue with the dip, as i'm thinking that switch should be set to OFF/open.

switch test will tell you if the switch on the cab is working or not. (you probably know this and tried it).

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Turn the dipswitch off, then carefully measure continuity between the two posts directly behind that switch on the pcb. If they're connected, that switch is bad. They're like 50 cents.
 
Ok looks like the problem might be slightly larger. None of the dipswitches seem to work. No matter what I flip the switches to on the first or second bank of switches, the dipswitch test shows no change. Anyone know what might cause both sets of dipswitches to stop working?
 
Ok looks like the problem might be slightly larger. None of the dipswitches seem to work. No matter what I flip the switches to on the first or second bank of switches, the dipswitch test shows no change. Anyone know what might cause both sets of dipswitches to stop working?

ohh crappy, my guess would be a bad solder joint or broken trace or bent solder legs touching. go over the back side of the board and make sure none of the legs on anything is touching another leg, look for damage to the board on any of the traces that go to the dip banks.

try what lyonsarcade said also
 
I looked up the schematics on that board, there's 1 line that 'enables' the chips that read the dipswitches. Since both banks of dipswitches are bad, you can assume (HAHA) that the dipswitches both didn't die, and the two chips that read them both didn't die, but there's an issue with either the chip that creates that 'dipswitch enable' line, or that line is actually cut.

It may be something else but that would be what I suspect, like dude above said it could easily be a scratch on the back of the board.
 
Awesome - thanks!

I looked up the schematics on that board, there's 1 line that 'enables' the chips that read the dipswitches. Since both banks of dipswitches are bad, you can assume (HAHA) that the dipswitches both didn't die, and the two chips that read them both didn't die, but there's an issue with either the chip that creates that 'dipswitch enable' line, or that line is actually cut.

It may be something else but that would be what I suspect, like dude above said it could easily be a scratch on the back of the board.
 
Well I've become the proud owner of this machine now. Which chip enables the dips? I've got the schematics in PDF but viewing them at a readable size is pretty taxing on my machine so I'm having a hard time finding the right one. Guess I could just print all 20 pages or so of the schematics. I've got other issues but I'll start a different thread to keep them straight.
 
So I looked over the schematics and found the chip that enables the others, UH7 pin 4 but the output of that matches the input on the other chips so it doesn't look like the line is cut. I also compared it to my other NBA Jam board that works fine (mostly) and those chips had the same outputs at least as far as my logic probe says. Also when I go into the dip switch test menu, it doesn't just have them all off, some are on and some are off. I tested the actual dip switches and they are fine. And the same switches are on/off every time I power up the machine, so something thinks they are stuck in that position. Where can I check now?

Scott
 
Looks like some thing is not reading the current position of the switches.
while it could be uh7 because pin 4 is the dip switch enable line.
it could also be RN17 that it is floating it may just lag enough that it will not read.
Make sure there nothing shorting the empty UH24 spot ( Printer port )
Check the voltage on RN18 and RN16 pin one should be 5 volts.
Pin #19 on on UH3 UJ3 might be stuck high or low That is the pins that go to UH24.
Pin #1 on UH3 and UJ3 are your dip switch enable and you should be able to see it toggle.

As many here suspect, It is something common between UH3 and UJ3 that preventing the board to read the dip switches.

Dip switch enable signal is common the Pull up resistor RN17 is tied to the signal.
5 volts to the pull up resistors RN18, RN16 are common.
Pin# 19 on UH3 and UJ3 are common which is tied to the not used UH24
 
Bingo! Pins 19 on UH3 and UJ3 are supposed to go to UH24 pin 19, but that link was broken. I connected a jumper wire and now it reads the dips normally. Problem solved!

But now I'm still having the same issues as my other NBA Jam with random sound samples played at the wrong time. Two main boards (TE and non-TE), two sound boards, two ribbon cables and the same weird sound issues. I checked the voltages and I'm getting about 5.1V on the chips. I've also gone as low as 4.8 and nothing makes the problem go away. Bad power supply perhaps?

Thanks again helping me solve the original problem.
 
Bingo! Pins 19 on UH3 and UJ3 are supposed to go to UH24 pin 19, but that link was broken. I connected a jumper wire and now it reads the dips normally. Problem solved!

But now I'm still having the same issues as my other NBA Jam with random sound samples played at the wrong time. Two main boards (TE and non-TE), two sound boards, two ribbon cables and the same weird sound issues. I checked the voltages and I'm getting about 5.1V on the chips. I've also gone as low as 4.8 and nothing makes the problem go away. Bad power supply perhaps?

Thanks again helping me solve the original problem.

awesome, i need to get myself a logic probe.

so your other NBA Jam you've swapped the main and sound boards twice (along with the ribbon cable)? if so sounds like it's a cab issue not a board issue.
 
Just from the top of my head.
I would look at something that is common between both setups.

Here is a few things you might want to look at.

Have you tried another Power supply?
It might be a weak power supply that might cause the sound card to trigger at the wrong time.

I had noisy audio issues due to the ribbon cable. Replacing the cable fix those issues.

I am thinking the sound card is not getting the right signals. Maybe the signal is floating Because of a cap that is shorted or a resistor that is open. This would cause the signal levels to change and make the sound card work in a random fashion.

Maybe a by pass cap on the IC chip (Main board) is open causing the chip to not not have the power it needs thus triggering at the wrong times.
 
Bingo again...I went back to try some stuff out and from the very beginning I noticed the marquee light would flicker a lot. I figured it was either the bulb or the starter so I reseated the bulb to see if that fixed the light problem. That fixed the light problem and this time when I plugged in the boards....the sound problem went away...on both boards. Weirdest problem I've ever experienced. Must have been a weird frequency thing or a power surge.

Thanks again for everyone's help!
 
A weak power supply would be affected by the light in the marquee.

If I may suggest something? Replace your power supply. It sounds like the power supply is getting weak. If you replace it now, It might prevent more problems later on.

Or you can look for the Large cap(s) after the bridge rectifier in your switching power supply. I almost willing to bet it is drying out or out gassing. If you replace the cap, The issues of the lights going out and affecting the power supply should go away.
 
Scott, I still have those 3 power supplies you tested. If you want one let me know. Hopefully I didn't pack them yet - I think I may have :(
 
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