TNMT Konami strange problem

[vas123]

Hello everyone,

I have a TNMT board which has a strange problem. At startup it passes the test and freezes when the clouds appear on the screen. When I put it in test mode everything is ok and works. In a sound test, I don't hear anything I choose. I checked all the eprom and they are ok. The sockets on the chips are perfectly clean.

Thanks for the advice in advance!

 

[TheDaddy]

Have you checked your voltages to make sure they are all correct ??

Normally a sound issue would not cause the board to freeze either.

Dave.

 

[SUPERSPRINT]

I had a tmnt that would reset after a minute every time, turned out to be a dodgy power supply.

 

[vas123]

The power supply is perfect. All voltages are absolutely accurate, and I checked them for pulsation with the oscilloscope. I have added additional capacitors at 120,000 uF on every voltage.
vas1232020-06-11 10:52:51

 

[AMS]

You can always sell it cheap to me.. maybe I can help you with the problem then

But I had the same issue in some Konami board and I had up the voltage a tad to get it running.

 

[Monstermug]

Some konami boards will freeze on sound problems too. After setup if it will allow, go into test menu and do a Mask Rom Test if that is an option. Let me know what happens

 

[vas123]

All test exept sounds test is ok .

 

[mlynn]

The only thing I know about TMNT is that the sound is mono, so if the one speaker is broken you'll get no sound.

 

[GadgetFreak]

It looks like it's freezing right at the point where the Ninja Turtles sound sample is played. You need to check the sound circuit, most likely the sample playback. If I remember correctly the sample is clocked through using several 74ls163's. Not heard of it freezing a board before though.

 

[vas123]

i replaced x1 and x2 640 kHz, pcb is still frezee.

 

[Monstermug]

Assuming there is absolutely no sound, you might want to check the z80 and sound ram? Or even the LS163's Aaron has mentioned. Schematics are available for TMNT. A good page dedicated to the voice samples too. An audio probe might come in handy just to eliminate an analog fault but I shouldn't think an analog fault will freeze the game, which leads me to think it's more a digital fault. It could also be two separate issues as well so I wouldn't dismiss that.

 

[vas123]

The Konami 007232 PCM controller is showing activity on the CPU lines,
it has power, and it's getting a clock signal, but the ROM address and
data lines are stuck low with no activity .ROM pins 14,16,18,20,23,25,27





Any ideas?

vas1232020-06-13 08:16:39

 

[TheDaddy]

Could be Ram / Rom ?

Is there any activity before it freezes ??

Dave.

P.S as I said its strange as audio faults don't normally cause this. If the main CPU has froze then there will be no signal to Audio CPU and this will stop the audio from working and give Low signals.

 

[vas123]

Hi, Dave,

I cheked all eproms ,and the status was good. No, activity before it freeze, but X2 640 Khz. resonator is connected to sync signal on custom konami chip is freeze both with picture.

Regards!

vas1232020-06-13 12:35:01

 

[TheDaddy]

Could be the Custom then, But on saying that it could be anything I suppose we are just guessing. Without physically having the board there is not much else I could advise.

Dave.

P.S I have not done any of these but I know the customs ruins a lot of simpsons / TMNT boards.

 

[vas123]

I pulled out custom chip Konami 007232 and ... still pcb freeze on the clouds.Now i am looking for a new chip to replace it.

 

[Ace`]

More likely to be the Z80 or work ram. I've never seen a bad 007232.