Kung Fu Master Bootleg No Sound?

Stoog

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Hey everyone

Thought i would have a look at this Kung Fu Master ive had for awhile

Works fine but no sound

Amp side of things is working fine but it seems that from the sound cpu to the AY8910 nothing is going on. I get healthy activity from sound cpu and the IRQ is working correctly but thats about it changed out both AY8910 as i had these fail in the past and do odd things like this before but still no go. I am not getting anything on pin 38 of either AY8910 and seems both are just sitting there doing nothing what so ever. Sound eproms data/address lines all look healthy and running as normal but for the life of me can't work this one out

I have 2 of these pcbs doing the same thing

Any ideas?
 
I think you should try to replace the sound CPU.From what I remember it's a Hitachi 6803, I have two Kung Fu Master PCB and this CPU was bad in both.
 
Ok ill give that ago that was my next step but not sure if i have any on scrap pcbs have to hunt around for one and if its any good thats another question
 
Sadly i tried 3 cpus and still the same thing really got me beat this

I think that first you have to determine the nature of fault, if digital or analog.Check with an external amplifier is some kind of sound comes from the two AY8910.If not, the problem is in digital circuit so check the CPU/RAM/ROM system and all related logic.
 
its digital side as said on first post its not track or broken connection problem been over the whole section

roms are fine and working correcrly i have inputs on cpu irq ect all vaild siginals but nothing coming out of cpu on all 3 i tried going to dig out my moon patrol and test them cant see all 3 would be buggered but anythings possible

this is the same issue on both boardsets i own anyway ill have anothe look when i get time see what i find
 
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Had a win seems that one of these AY8910s is faulty or just doesn't like to work together with another one. Seems if i run this in my Elevator Action on its own at IC63 works fine put it into Kung Fu Master with the other one refuses to work and pulls down the output lines from CPU. This also happens in Moon Patrol so now that AY is retired to the bin

So fitted another known good one into Kung Fu and all digital sounds came back to life and cpu working correctly

Just for fun i tested the 3 CPUs in my working Moon Patrol and all worked fine so wasn't a cpu issue after all

Cheers
 
It was not very difficult to find this issue, digital circuit is not really complex.If CPU was not the culprit, they were the AY8910 for exclusion :)
 
Yes i know that but thats why it was doing my head in because this certain AY that had issues tested OK in another board set but only on its own not paired together with another one. Thats why i was like what am i missing here anyway just happy its working now well one of them anyway :)
 
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Yes i know that but thats why it was doing my head in because this certain AY that had issues tested OK in another board set but only on its own not paired together with another one. Thats why i was like what am i missing here anyway just happy its working now well one of them anyway :)
Glad to hear you got it fixed.

What pinot does this board use? I have one I'd like to test. Thanks.

Scott C.
 
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