Hi guys,
I'm Carlo from Italy. I've a Data East Last Action Hero and, from a couple of months I'm in front a one strange issue.

The sound works properly for 30 seconds / one minute of the first game, after that, the sound board stops to play new sounds or music and repeats indefinitely the latest sound (that every power off-on change random).

I suppose that there is something around the protocol from the microcontroller to the sound board, or any electrical disturb that lock the sound board (i bought the pinball with the sound board already modded with some capacitors maybe to filter something).

Can you help me to found a solution? I'm a technic and I've a scope, Where I can lock? Ripple on voltage level or signal on the protol ???

Thanks in advance
Carlo

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Thanks drummermike I've unplugged and plugged some time the connectors. I also used isopropyl alcohol to clean the contact. But the issue continue

Thanks BleacherBum maybe tomorrow i will try to check with my oscilloscope. Really I have an other minor issue with the power supply. When the pcb is cold, the pinball needs one ore two minutes to start. Now the pcb is not cold so I not see strange values and the pinball starts in less than one second. Any suggestion where I have to focalize my research? What voltage line is critical?

In the midtime I ordered new capacitors to replace the one on the sound board. I have to do the same on the power spply board?

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Finally I've checked the voltages

I found:
+5VDC line (CH1 yellow) 5.08V no ripple
+12VDC UNREG line (CH2 blue) 10.5V high ripple 1.12V pp
-12VDC UNREG line (CH3 purple) -13.7V no ripple
+12VDC "regulated" line coming from VR1 (CH4 green) 12.2V no ripple

I also found a strange behavior on +5VDC. For this I will open a new topic anyway the issue is that the at cold power on the voltage is 3.5V with 440mV ripple, and it stabilize to 5V no ripple in more ore less one minute

I also store how drop the voltages on power off, to evaluate the the goodness of the capacitors.
+5VDC line (CH1 yellow) drop fast at power off
+12VDC UNREG line (CH2 blue) drop fast at power off
-12VDC UNREG line (CH3 purple) drop slow at power off
+12VDC "regulated" line coming from VR1 (CH4 green) drop slow at power off

Now,
1) do you think that the ripple on +12VDC UNREG is too high?
2) do you think that the line +12VDC UNREG is too low?
3) do you think that at power off the line +12VDC UNREG and +5VDC drop too fast (maybe inefficient electrolytic capacitors)?

Thanks in advance to who will help me
Carlo

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Hi,
I've changed all CAPS and fixed the issue on delay on 5V line

Now I continue to have this issue on sound board

In the link below you can see what happen:

Occasionally, after some second of good sound, the sound board repeat the last sound, some time keep silent, depending by what sound is reproducing during the stop.

Any idea in what I've to search?

Also during the parametrization, without solenoid or lamps working, the sound board stops to sound

Thanks in advance

Hi,
I've an update.
I tried to swap the ribbon cable and check it under a microscope but no improvement

Now I'm checking the signals on the cable

I noted that the BUSY signal is always at a high level except for a few short pulses at low level when the sound board has to reproduce a new sound, while it remains constantly low when the sound board is blocked.

Does anyone have an idea why the BUSY signal can hang low?

If I don't solve the problem with the help of some of you, I have a possible trick in mind. I noticed that when the sound board is blocked, if I force a reset by putting low the RESET line that comes from the ribbon calble, the sound board restarts (then the BUSY signal comeback high). I could put a small uP that checks the status of the BUSY signal and when it sees it low for more than two seconds it puts the RESET signal low for a few millisecond.
The only drawback is that the sound board reproduces the phrase "I'll Be Back" when it is turned on.

What do you think?

Please help me, your commer are very apreciated

Ciao from Italy

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Bax1 do you mean the chip connected to the connector CN21?
I can't see yhe wiring diagram un the link. It seems a local link
I don't know "pia" acronym, could you explain me?

Thanks

Solved!

I noted that the Chip Select of one eprom od sound board change modulation continuously except is the sound board is frozen
I used a tiny chip to monitoring the on CS and perform a res in case of sound board frozen.

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