Crazy Kong sound issue

[Belike]

As most of you know, we are a big fan of the different versions of Crazy Kong pcbs with Etienne.
I bought an original Falcon blue pcb a few weeks ago, made a jamma adapter for it (Thanks for the assistance Etienne ) and made some tests yesterday.
For first test, the graphics was 100% ok, but the marching, jumping and some other sounds were missing.
I made some eprom reseating, etc. and now it also has graphic faults.
I guess I can fix that with some more cleaning and reseating, but I would need some help with the missing sounds.
Where should I start?
Here is a little video:
http://www.youtube.com/watch?v=8FK52PedKEo
Thanks in advance.

[ataritoobin]

I'm not too familiar with Crazy Kong PCBs, but it sounds like the sampled "Crazy Climber" sounds are missing.  Might check the DAC circuitry (again keeping in mind I'm not familiar with these particular PCBs  )

[PaulSwan]

The schematics are available at crazykong.com. The digital audio (as opposed to the 8910 audio) pops out of an LM3900. I'd check for audio out there and also if there is digitial sample data feeding it out of the LS157.
Paul.

[Belike]

I checked that area and I found some scratches on solder side, right under the LM3900.




Btw. how can I check the audio outs from those chips you mentioned?

[PaulSwan]

Oscilloscope or crystal earpiece. You might be able to get away with a headphone. For the digital side, a logic proble or oscilloscope.

Paul.

[Etienne MacGyver]

I adviced you to "beep" those traces remember 

if they are broken, scratch a little more of the blue away and solder it, or apply a jumper wire.

[Belike]

I adviced you to "beep" those traces remember  

if they are broken, scratch a little more of the blue away and solder it, or apply a jumper wire.

Thanks Etienne, I just received my first multimeter from my old friend, I will try that also.
The ic-s that Paul mentioned are  available here for some cents, I will also try the piggyback method.

[level42]

You can use the ESR meter to measure this too...

[Belike]

You can use the ESR meter to measure this too...

Can you explain the method in a few words?

[level42]

Instead of putting the leads over a cap you put them over two solder points with a track between them that you think may be broken. Then look at the screen. Not sure about the Peak-Delta, but the Russian meter will say R ONLY to indicate it didnt find a capacitor but only a " resistance" and then show the resistance in Ohms.

Remember, its an ESR meter, the R stands for resistance, so it is a ....resistance meter. A track of copper and some solderings should of course indicate a very low resistance if they are OK.....

[Belike]

Instead of putting the leads over a cap you put them over two solder points with a track between them that you think may be broken. Then look at the screen. Not sure about the Peak-Delta, but the Russian meter will say R ONLY to indicate it didnt find a capacitor but only a " resistance" and then show the resistance in Ohms.

Remember, its an ESR meter, the R stands for resistance, so it is a ....resistance meter. A track of copper and some solderings should of course indicate a very low resistance if they are OK.....

I'm starting to understand electricity, thanks André!

[liquidx]

Instead of putting the leads over a cap you put them over two solder points with a track between them that you think may be broken. Then look at the screen. Not sure about the Peak-Delta, but the Russian meter will say R ONLY to indicate it didnt find a capacitor but only a " resistance" and then show the resistance in Ohms.

The Atlas/Peak will display "In Circuit/Leaky" and the Resistance below.

[Belike]

The Atlas/Peak will display "In Circuit/Leaky" and the Resistance below.

Exactly.

[Belike]

I bought the ic-s that Paul mentioned and piggybacked them.

After the first test, the missing sounds was there, but they were quite weird.
I had an instant idea and removed the LS 157 and with just the piggybacked LM3900 the result was the following:
http://www.youtube.com/watch?v=BadFclnoqH4
Thanks Paul, you are a genius!
I owe you one, but please everything but not the Space Pirate!
Of course thanks to all of you for your advises also.

[Etienne MacGyver]

Cool!

Now cut that old one out, desolder the remains, put in a socket in there and your ready for the next challenge; the graphic issue..