sequential circuits drumtraks dead voices

[selfpreservation]

anybody have any experience with drumtraks and dead voices kik dont work nither do the toms all voice chips are present

[electoyd]

is it that the pads are just unresponsive?  could it be the pads just need cleaned they get clogged up with crap and no connection is made.  I've certainly had that problem with a few old machines,  I know the drumtraks is a really old machine.

[Circuitbenders]

if it is the voice eproms then the chip images are out there somewhere. I looked into it vaguely a while back when someone enquired about this exact problem. Unfortunately they never actually sent the thing to me so i never worked out what was wrong with it.

I guess the first thing i'd try would be swapping the eprom for a dead sound with one from a working sound, and see if that works, assuming they all use the same IC's. That way you could work out if its as electoyd says, and its the triggering rather than the actual sound data.

[selfpreservation]

if it is the voice eproms then the chip images are out there somewhere. I looked into it vaguely a while back when someone enquired about this exact problem. Unfortunately they never actually sent the thing to me so i never worked out what was wrong with it.

I guess the first thing i'd try would be swapping the eprom for a dead sound with one from a working sound, and see if that works, assuming they all use the same IC's. That way you could work out if its as electoyd says, and its the triggering rather than the actual sound data.

its a friends the sounds dont trigger over midi either so that rules out the pads i guess , he had a few extra roms and i think he swapped one of them for the toms but no joy ,( the kik has a completley different chip for some reason )but we dont know if they work either , there is a row of tantalums which always ring alarm bells in old machines , i cant find a schematic anywhere on the web does it even exist? , ii dont own it so im not that biothered   i just thought someone on here maybe had some knowledge of these cause thers hardly anything on the web, wine and country do the roms $15 each they do custom voices too its a nice machine actually has some nice features he bought it for £30 last week with an mks 70 and pg800 for £60 i seriously slept in 

[Gordonjcp]

I've got a circuit diagram *somewhere* I think.  If I recall correctly each voice has its own DAC and filter.  The filters may be gubbed.  Trace back the data pins of the ROMs and see where they go to, I can't remember if it's something like a DAC08 chip (probably not - it's using a non-linear DAC) or an R/2R ladder, but somewhere it should pass out to the filters.  Ensure the filter ICs are good - swap one from a good channel with a faulty channel.

I take it you've checked the PSU voltages and stuff?