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gorgar sound gremlins

stevebm1

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10 Years
Joined
May 26, 2014
Messages
1,698
Location
uk
hi,my gorgar seems to have a sound issue,it starts up fine with all sounds and speech,but after 10 minutes,he starts talking random words then I loose all sound and speech,if I turn off and restart,all sound and speech comes back,but again after about 10 mins the problem comes back,im running a rottendog board,with original williams sound and speech board,and original williams power supply,but I do have the original mpu/driver boards,just not fitted,as they had issues.I do have a cap kit for the soundboard,but I have not fitted it,as the sound was all working fine,for the first couple of weeks,when I first got it up and running
 
6810 RAM IC on the sound board is the most likely cause of the symptoms you describe.

There is no gaurantee though, as it could be any logic fault really, it would need a proper diagnosis. The 6810 is also most likely soldered in, so you can't just swap it to try it
 
thanks for the replys guys,im sure the sound board is the same as in defender and robotron,just the jumpers are set different,am I right?
 
Hey, @lukewells, why would the 6810 RAM be the most likely culprit? Do they have a tendency to fail slowly with ever-increasing read/write errors? I know you're knowledgeable in this area so this is a genuine enquiry, not a dig! Please feel free to get technical! ;)

As the problem seems to take a while to build up I'd be thinking iffy power and/or dodgy caps. I'd definitely be checking capacitors on a game this age - I pretty much replaced them all on my 35-year old Paragon. As you have it already no harm in fitting the capacitor kit. The electrolytics will be bone dry by now and well past their useful life expectancy.
 
Sorry I don't have an interesting technical explanation, it's just a fault I have seen quite a few times over the years, as these sounds board are very common in both early Williams pins and most of the Williams videogames.

My Jungle Lord is currently doing this, so I need to go and retrieve the sound board from it when I get chance and fix it
 
Experience counts for a lot. After doing stuff for a while you get know what the common faults are. I guess it's similar to the 5101 RAM on the Bally MPU board. I popped in a new one those on my acid damaged -35 and it came back to life.

Sorry, @stevebm1, didn't mean to hijack your thread! Hopefully between replacement chips and caps you'll get it working properly. Keep us posted!
 
well ive recapped the board,will fit it later and see what happens,fingers crossed,or else it's time to pull off the ram chip as luke suggested,at least it's not a big chip,I did a 680000 on an arcade board the other day,that bstd took ages
 
Don't assume its the ram, just saying it is a very common cause of the sound going mental and then cutting out.

Maybe try leaving it to warm up and fail, then blast the ram with a shot of freeze spray to see if it brings it back to working
 
just tried it,and all was well for 20 mins,so I thought great,fixed it,then got a random "speaks" and sound went again:(,tried switching it off and on as that had fixed it in the past,but nothing,left it for 20 mins,switched it on again,and sound came back for 10 mins,then went again.:hmm:,guess i'll order a new ram chip
 
the weird thing is when sound dies a death,if you press the test switch on the soundboard,you still get all sounds and speech,im running off a rottendog board,so I doubt the problem lies there
 
the weird thing is when sound dies a death,if you press the test switch on the soundboard,you still get all sounds and speech,im running off a rottendog board,so I doubt the problem lies there

With the test switch working it suggests that the sound board is working correctly and that the issue is either the rottendog MPU or connections to/from it to the sound board or their connectors.
 
I was thinking the same as @Moonraker. Odd that the test button works even when the sounds are failing mid-game. You mentioned that you do have the original MPU but it had issues. Any chance you could refit it and at least have the machine on long enough doing something to see if the sound goes the distance? That would almost certainly rule out a sound board issue and put the Rottendog in the spotlight.
 
Interesting ...

If sound works when you press the test button, then it sounds like the control signals are at fault. Do you have a scope you could stick on the lines?
 
no sadly I don't own a scope,when I get some time at the weekend i'll try and check/reseat the connectors and see if that helps
 
ok,bit of an update on this,my power supply board,which has been recapped is only giving me 4v on the top header(is this normal?),so I wonder if that is part of the problem,im tempted to run a 5v feed from a jamma power supply(just for test purposes) to see if that makes a difference,the ram chip luke suggested to check does not get hot,but the big socketed chip closest to the ribbon cable does
 
Very likely, If your CPU board is only getting 4v (from the PSU) then it might not be able to make a valid logic "high" signal on the control lines to the sound board
 
If you are going to use a switcher psu, then make sure you common the ground wires and make sure the exiting +5v from the pinball psu is isolated
 
ok,bit of an update on this,my power supply board,which has been recapped is only giving me 4v on the top header(is this normal?),so I wonder if that is part of the problem,im tempted to run a 5v feed from a jamma power supply(just for test purposes) to see if that makes a difference,the ram chip luke suggested to check does not get hot,but the big socketed chip closest to the ribbon cable does

You already said the answer - run a separate 5v feed from a psu to see if it works or not. If it does then you need to find out why there's only 4v, if it doesn't then the problem lies elsewhere. :cool:
 
4V does not sound like a good voltage for the logic section of any electrical device! ;) It might only be 1V out but that's 20% below ideal. I'd definitely be taking a closer look at that...
 
ok so I hotwired in a jamma power supply,and it worked fine for 30 mins,but then sound went again the 6802 processor on the soundboard is red hot when sound stops working,it you let it all cool down,it works again,but then cuts out again,once the chip gets hot,so is the 6802 faulty,or is something else making it warm up?
 
Replace the 6802 and repeat the test... If the replacement get's hot then it's something else causing it. Probably best to replace the old 6802 due to heat damage anyway.
 
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